小学二年级寒假英语练习题可打印
对于学习语言来说,为了对付考试而做题,确实有一定的帮助和重要性,那么关于二年级寒假英语练习题怎么写呢?以下是小编准备的一些小学二年级寒假英语练习题可打印,仅供参考。
小学二年级寒假英语练习题可打印【篇1】
1、Mary is a girl of ten.Her parents are teachers.She loves them.She likes eating many things.She likes sweets,meat and ice cream.She doesn't like noodles.
(1)Mary's mother and father are teachers.( )
(2)Mary is nine years old.( )
(3)She likes noodles.( )
学习啦在线学习网(4)She doesn't like meat.( )
(5)She doesn't like sweets.( )
学习啦在线学习网2、Amy:What do you like,Sam?
学习啦在线学习网Sam:I like football.
学习啦在线学习网Amy:Here's a present for you.
Sam:What is it in your bag?
Amy:It's a football.
Sam:Thank you.
(1)Amy likes football.( )
(2)Sam likes football.( )
(3)Here's a present for Amy.( )
(4)Here's a present for Sam.( )
(5)It's a basketball in the bag.( )
小学二年级寒假英语练习题可打印【篇2】
1、Oh! So many animals. One orange cat is on the bed. Two yellow cats are on the chair. Four birds are in the box. One black cat is under the desk. Three dogs are on the desk.
学习啦在线学习网(1)There is one orange cat. ( )
学习啦在线学习网(2)There are two yellow cats.( )
(3)There are five birds. ( )
学习啦在线学习网(4)There are two dogs.( )
(5)Two orange cats are on the chair.( )
2、This is a big zoo.Look,that's a big lion.The small lion is her baby.They are scary.Oh,look at the pigs.They are very fat.They are cute.What are these over there?They are pandas.Thet are lovely.They are black and white.
(1)This is a big park.( )
(2)That's a big lion.( )
(3)The small lion is her baby.( )
(4)The pigs are big.( )
(5)The pandas are black and white.( )
小学二年级寒假英语练习题可打印【篇3】
学习啦在线学习网1、Mary is a girl of ten.She likes swimming very much.But she doesn't like cycling,so she goes to school on foot every day.And she likes red.She has a lot of red clothes.
学习啦在线学习网(1)Mary is eleven years old. ( )
学习啦在线学习网(2)Mary likes cycling. ( )
(3)She walks to school every day. ( )
(4)She doesn't like red.( )
(5)She doesn't have red clothes.( )
学习啦在线学习网2、An old woman had a cat. The cat was very old; she could not run quickly, and she could not bite, because she was so old. One day the old cat saw a mouse; she jumped and caught the mouse. But she could not bite it; so the mouse got out of her mouth and ran away, because the cat could not bite it.
Then the old woman became very angry because the cat had not killed the mouse. She began to hit the cat. The cat said, "Do not hit your old servant. I have worked for you for many years, and I would work for you still, but I am too old. Do not be unkind to the old, but remember what good work the old did when they were young."
(1)An old man had a cat.( )
(2)The cat was very old.( )
学习啦在线学习网(3)The old woman became very happy.( )
(4)The cat can kill the mouse.( )
学习啦在线学习网(5)The old woman was killed by mouse.( )
小学二年级寒假英语练习题可打印【篇4】
Van and Ted are twin brothers. They look the same. They are English. They are eleven. They are in No.15 Middle School. They are new students in Class One, Grade One. Van sits in Row One. Ted sits in Row Three.
学习啦在线学习网( )1. Van and Ted are ___.
学习啦在线学习网A. twins brothers B. twin brother C. twin brothers
学习啦在线学习网( )2. They are___.
A. English B. American C. Chinese
学习啦在线学习网( )3. They are___.
学习啦在线学习网A. ten B. eleven C. twelve
( )4. They are___students.
学习啦在线学习网A. new B. old C. good
学习啦在线学习网( )5. Ted sits___Row Three.
A. on B. in C. at
解析:
学习啦在线学习网1.C.从文章第一句Van and Ted are twin brothers.“Van和Ted是双胞胎兄弟。”可以得出答案。
2.A.从文章第三句They are English.“他们都是英国人。”可以得出答案。
3.B.从文章第四句They are eleven.“他们十一岁。”可以得出答案。
4.A.从文章第六句They are new students in Class One, Grade One.“他们是一年级一班的新生。”可以得出答案。
学习啦在线学习网5.B.从文章最后一句Ted sits in Row Three.“Ted坐在第三排。”可以得出答案
小学二年级寒假英语练习题可打印【篇5】
My name is Jim Green. I am twelve. That is my mother. She is a teacher. That is my father. His name is Jeff Green. He is a teacher, too. He is an English teacher. That is my sister, Kate. She is eight. This is Polly. It is a bird. It is a parrot.
学习啦在线学习网仔细阅读下面的题目,正确的写"T",错误的写"F"
( )1. Jim Green is eleven.
( )2. His mother is teacher.
( )3. His father is a Chinese teacher.
( )4. His sister is twelve.
( )5. He has a bird.
解析:
学习啦在线学习网1.F.从文章第二句I am twelve.可以得出答案“Jim Green是12岁,不是11岁”噢。
2.T.从文章第四句She is a teacher. 可以得出答案。
学习啦在线学习网3.F.从文章第八句He is an English teacher.可以得出答案:Jim的爸爸是英语老师,不是语文老师。
学习啦在线学习网4.F.从文章倒数第四句She is eight.可以得出答案:Jim的妹妹Kate是8岁,不是12岁。
5.T.从文章最后三句: This is Polly. It is a bird. It is a parrot.“这是Polly,是只小鸟,它是只鹦鹉。”可以得出答案。
小学二年级寒假英语练习题可打印【篇6】
Thereisanewparknearmyhouse.Itsafinedaytoday.MyfamilyandIareintheparknow.Onmyleft,thereisacafe.Onmyright,thereisabiglake.Therearemanyflowersandtreesnearthelake.Theresasmallhillbehindthelake.Nearthelake,thereisasign.Itsays,Dontswiminthelake!Thereisaplaygroundinthemiddleofthepark.Therearesomesmallshopsnearthegate.Theparkissobeautiful.Welikeitverymuch.
( )1.Theparknearmyhouseis_____.
A.newandbeautifulB.oldandbeautifulC.cleanandnewD.oldandclean
( )2.Isthereacafeinthepark? ______
A.Yes,thereisnt.B.No,thereisnt.C.Yes,thereis.D.No,thereis.
( )3.Peoplecant_______inthelake.
A.swimB.fishC.boatD.play
学习啦在线学习网( )4.Theshopsintheparkarenot_______.
学习啦在线学习网A.smallB.bigC.goodD.pretty
( )5. -Dowelikethepark? -________
学习啦在线学习网A.Yes,wedo.B.No,wedo.C.Yes,youdo.D.No,wedont.
注解:
1.A-从短文第一句Thereisanewparknearmyhouse.在我家附近有一个新的公园。和倒数第二句Theparkissobeautiful.这个公园很漂亮。可以得出答案newandbeautiful.
小学二年级寒假英语练习题可打印【篇7】
一、情景选择
1.你想问别人几年级,应说________________。
A.What class are you in ?
B.What grade are you in ?
学习啦在线学习网2.当你想知道这些动物是否是猫,应说_____
A.Are these cats ?
学习啦在线学习网B.Is this a cat ?
3.当你想问别人擅长什么,应说________________。
学习啦在线学习网A.What are you ?
学习啦在线学习网B.What are you good at ?
4.你想问别人有关数字的问题时,应说__________。
学习啦在线学习网A.How many books can you see?
学习啦在线学习网B.What can you see ?
5.你想把东西递给别人,应说________________。
A.Here you are .
B.Thank you .
二、判断 正确T 错误F
My name is Liming. I am a boy. I am from Beijing. I have a good friend.
Her Chinese name is Fangfang. Her English name is Eve. She is a nice girl. She is twelve.
She is in Class Two, Grade five. She is good at dancing. We all like her. Her father is a doctor and her mother is a nurse.
They are in a hospital. They love Eve and Eve loves them, too. Eve has a happy family.
学习啦在线学习网1.Liming is from Guizhou. (TF)
2.Eve is in Class Five, Grade Two. (TF)
3.Eve is good at dancing. (TF)
4.Eve’s father is a doctor . (TF)
学习啦在线学习网5.Eve’s father and mother are in a school . (TF)
小学二年级寒假英语练习题可打印【篇8】
一、单选
1. Do you like spring ? Yes, I _______.
A.can
B.do
2. Can I help you ? -----________
学习啦在线学习网A. I’d like a coat.
B. I like tigers.
3. Where’s the car?-----________
A.OK.
B. It’s on the sofa.
4.What can you see ? -----________
学习啦在线学习网A.I can jump.
学习啦在线学习网B. I can see a train.
学习啦在线学习网5.What do you have ? -----________
A.I have a doll.
学习啦在线学习网B. I like dolls.
学习啦在线学习网6.What lessons do you have ?-----________
A.We have PE and Art.
B. I have a yo-yo.
7.It’s time to go to bed. -----________
A. Goodbye .
B. Good night.
学习啦在线学习网8.Let’s count the -----________
A. jeep
B.jeeps
9.Let’s keep the water clean.的中文是什么?
A.我想要一杯水。
B.让我们保持水源的干净。
学习啦在线学习网10.It’s time to go home.的中文是什么?
A. 是上学的时间了。
B. 是回家的时候了。
小学二年级寒假英语练习题可打印【篇9】
一、左右搭配,连线。
学习啦在线学习网1. What time is it? 让我们一起踢足球吧。
2. It`s twelve twenty . 几点了?
3. Let`s play football. 十二点二十了。
学习啦在线学习网4. It`s playtime . 你在哪里?
5. Where are you? 游戏时间到了。
学习啦在线学习网二、写出每个单词的首字母。
____onkey _____ir l _____ose
学习啦在线学习网____range ____ark _____um
学习啦在线学习网____o ____oy _____each
____other ____ood _____ame
小学二年级寒假英语练习题可打印【篇10】
一、选不同类单词
1.A.chickB.orangeC.duck
2.A.horseB.seeC.elephant
3.A.milkB.bedC.window
学习啦在线学习网4.A.doorB.singC.skip
学习啦在线学习网5.A.walkB.paperC.fly
二、选英文单词
1.母鸡
A.hen B.duck
2.绵羊
学习啦在线学习网Ashoe B.sheep
3.鼻子
学习啦在线学习网A.nose B.eye
4.朋友
A.fly B.friend
5. 大的
A.big B.bag
6.大象
A.panda B.elephant
7.铅笔
A.pen B.pencil
8.关
A.open B.close
9.房间
学习啦在线学习网A.road B.room
10.桌子
学习啦在线学习网A.taxi B.table
三、选择is和are
学习啦在线学习网1.There _____ a bag on the floor.
学习啦在线学习网A.is B.are
学习啦在线学习网2.There _____ 49 students in the classroom.
A.are B.is
3.There _____ an elephant in the circus.
A.are B.is
4.There _____ a banana and 5 apples in the table.
A.is B.are
5.There _____ 5 apples and a banana on the desk.
A.is B.are
四、单选
学习啦在线学习网1.What do you see?
学习啦在线学习网A.I see a duck. B.I have got a duck.
2.May I have a hot dog?
A.Yes, here you are. B.I am OK.
3.What can you do?
学习啦在线学习网A.I can fly a bicycle. B.I can ride a bicycle.
4.Where do you live?
A.I love Changde. B.I live in Changde.
学习啦在线学习网5.Who is your friend?
学习啦在线学习网A.Spotty is my friend. B.I have a friend.
小学二年级寒假英语练习题可打印【篇11】
一、选反义词
1.white
A.blue B.brown C.black
2. smooth
A.hard B.rough C.round
3. soft
A.hear B.hand C.hard
4. small
学习啦在线学习网A.big B.bag C.beautiful
5. cold
A.warm B.hot C.cool
二、单选
1. What ____ you see? I see a kite.
学习啦在线学习网A.do B.can
2. ______ is Ming? Beside the window.
A.Where B.What colour
3. What colour are the pens? ___ pink.
A.It’s B.They are
学习啦在线学习网4. _____ the apple.It’s smooth.
A.Touch B.Eat
学习啦在线学习网5. Down by the road waiting ___ the bus.
学习啦在线学习网A.for B.of
6. Happy birthday ______ you.
A.for B.to
7. Do you like hopping? Yes, I _____.
A.like B.do
学习啦在线学习网8. What can you do, Kitty? _____ can sing.
A.She B.I
9. Can you _____? Yes, I can.
学习啦在线学习网A.run B.running
学习啦在线学习网10. How many tigers? There is ____ tiger.
学习啦在线学习网A.one B.three
11.______ are they? They are oranges.
学习啦在线学习网A.What B.What colour
12. What food do you like? I like ___ salad.
A.eat B.eating
13. Can I help you? ________.
A.Here you are. B.A pen, please.
小学二年级寒假英语练习题可打印【篇12】
一、找出每组中不同类的单词。
学习啦在线学习网( ) 1. A .run B. read C. swim D .lamp ( ) 2. A. book B. bus C. ruler D. rubber ( ) 3. A. apple B. pear C. bear D. peach ( ) 4. A. eight B. cow C. four D. five ( ) 5. A. noodles B. gloves C. dress D. socks ( ) 6. A. desk B. door C. table D. cold 二、选择题
( )1. I ____ to sing.
A. am B. can C. like ( )2.______ do you live?
A. What B. Where C. Who ( )3.May I _______ some Coke?
A. has B. have C. have got ( )4.Have ________ milk.
学习啦在线学习网A. an B. a C. some ( )5. Do you like to dance? Yes, ____________.
学习啦在线学习网A.I can B. I do C. I am ( )6. Winter is ______ cold.
学习啦在线学习网A. the B. an C./ ( )7.Draw a bird ________ the ground.。
A. on B. to C. under ( )8. What __________is it? It’s green.
学习啦在线学习网A. / B. colour C. animal ( )9.“Oink, Oink”。 What do you _____?
学习啦在线学习网A. have B. hear C. look ( )10. It’s cold. ____________ your coat.。
A. Put on B. Take off C. Look at ( )11. How do you go to the park? __________
A. Get in the car. B. By car. C. Get off the car. ( )12. Have a biscuit, please. _________.
学习啦在线学习网A. I can. B. I like. C. Thank you. ( )13. Listen _____ the clock.
A. to B. in C. on ( )14.Green light! We can go_______.
A. stop B. fast C slow ( )15. Is it on the tree? Yes, _________.
学习啦在线学习网A. it not B. it is C. it is not ( )16. Go ________, spotty!
A. there B. here C. where
小学二年级寒假英语练习题可打印【篇13】
一、听音选出你所听到词。(2点×5=10点)
学习啦在线学习网( ) 1. A.make B. cake C. lake
学习啦在线学习网二、 ( ) 2. A. fast B. fork C. far
学习啦在线学习网( ) 3. A. chips B. chopsticks C. trousers
学习啦在线学习网( ) 4. A. sweater B. shirt C. shorts
( ) 5. A.feed B.speak C. read
二、听音选出你所听到的短语。(2点×5=10点)
学习啦在线学习网( ) 1. A.over there B.get out C.dragon boat
( ) 2.A.play football B.play basketballC.play
tennis
学习啦在线学习网( ) 3.A.jump far B.run fast C.swim fast
学习啦在线学习网( ) 4.A.watch TV B.listen to music C.do
Homework
学习啦在线学习网( ) 5.A.make a cakeB.make a planeC.make a kite
三、听音选出你所听到的问句。(2点×5=10点)
学习啦在线学习网( ) 1.A.What's this? B.What's that?
C.What are these?
( ) 2.A.Where is the bread? B.Where is it?
学习啦在线学习网C.Where is your book?
( ) 3.A.Is it Shangshan's ruler? B.Is this a ruler?
C.Whose ruler is it?
( ) 4.A.Can your Dad swim? B.Can you swim?
学习啦在线学习网C.Can your Mum swim?
学习啦在线学习网( ) 5.A.Can this dog run? B.Can this boy run?
C.Can this man run?
学习啦在线学习网四、听音选出你所听到的词。(2点×5=10点)
学习啦在线学习网jump winner far friends puddle
Sam and Amy are good_____.Amy can jump______.But Sam can't ______far.Amy is the_____.Sam can swim in the ________.
笔试部分(60点)
五、给单词归类(1点×10=10点)
学习啦在线学习网duck shorts noddles monkey sweater draw
shirt write bread drink
学习啦在线学习网1.动词---,---,---
2动物---,---,---
学习啦在线学习网3食品---,---,---
4衣服---,---,---
六、单项选择(2点×10=20点)
( )1.A:What are you doing?
B:We are making_____cake.
A.a B.an C.the D./
( )2.Please ____quiet! Your father is working.
A.is B.am C.be D.are
( )3. Children,please go ____your room!
A.in B.to C.and D.for
( )4.It's hard____English people to use chopsticks.
学习啦在线学习网A.with B.to C.for D.of
( )5.Do you use chopsticks____England?
学习啦在线学习网A.from B.in C.for D.to
( )6.Amy is a girl.She is playing _____flute.
学习啦在线学习网A.she B.her C.hers D./
( )7.My father is listening _____music.
A.to B.for C.at D.in
( )8.Tom is doing _____homework.
学习啦在线学习网A.he B.his C.him D./
学习啦在线学习网( )9.Mum __
学习啦在线学习网___watching TV now.
学习啦在线学习网A.am B.are C.is D.be
( )10.Let's make a kite____Tom.
A.to B.for C.at D.of
七、问答连线(2点×5=10点)
( )1.What are those? A.Yes,it can.
( ) 2.What are you doing? B.Yes,I can.
学习啦在线学习网( ) 3.Can you run fast? C.Yes,here you are.
( ) 4.Can I have an ice cream? D.I'm eating chips.
( ) 5.Can this dog run? E.They are dragoboats.
学习啦在线学习网八、连词组句(2点×5=10点)
1.ducks/are/these/naughty/very
_____________________________.
2.these/are/what
学习啦在线学习网_____________________________.
3.sweater/Sam's/this/is
_____________________________.
4.fast/run/you/can
______________________________.
学习啦在线学习网5.boats/dragon/are/they
___________________________.
九.阅读短文,选词填空(2点×5=10点)
学习啦在线学习网Sam is an English boy.He is seven years old.His mother is a nurse.His father is a doctor.His grandfather is a teacher of Chinese.Sam doesn't want to be a teacher or a doctor.He is going to be a policeman.
1.( )Sam is a/an______boy.
学习啦在线学习网A.English B.Chinese
2.( )His father is a ________.
学习啦在线学习网A.policeman B.doctor
3.( )His mother is a ______.
A. teacher B.nurse
学习啦在线学习网4.His ____can speak Chinese.
学习啦在线学习网A.father B.grandfather
5.Sam is going to be a _______.
学习啦在线学习网A.policeman B.doctor
小学二年级寒假英语练习题可打印【篇14】
学习啦在线学习网一、朗读、抄写并背默下列句子(抄一遍,默一遍,自行批改订正)
学习啦在线学习网1. What can you see, Alice? I can see two butterflies.
2. Touch this watch. Is it soft? No, it’s hard.
学习啦在线学习网3. Listen! What can you hear? I can hear a train.
4. Do you like hopping? No, I like riding my bicycle.
学习啦在线学习网5. Let’s go skating together. All right.
学习啦在线学习网6. What do you like eating? I like eating salad.
7. Do you like eating biscuits? Yes, I do.
学习啦在线学习网8. What are they? They are snakes.
9. Do you like elephants? No, I don’t. I like giraffes.
学习啦在线学习网10. The pig is lovely and soft. I like it very much.
学习啦在线学习网11. They are black and white. They have long tails. They can run fast. They like eating grass. What are they? They are zebras.
学习啦在线学习网12. Winter is cloudy and cold. I have a sweater and a coat for it.
学习啦在线学习网13. Autumn is nice. In autumn, we like eating fruit.
学习啦在线学习网14. Look at the light. It’s yellow. Don’t cross the road. Let’s wait.
15. Spring is warm. What do you have for spring? I have a shirt and trousers.
学习啦在线学习网16. Look, Kitty has a new skirt. It’s nice and pink.
学习啦在线学习网17. Can your mother play basketball? No, she can’t. But she can play cards.
学习啦在线学习网18. Here’s a carnation for you, Mum. Happy Mother’s Day !
学习啦在线学习网19. I’m hungry and thirsty. I want some milk and bread.
20. I’m sorry. That’s all right.
学习啦在线学习网21. I’m tired. I want to sleep on the bed.
22. This chair is hard and rough. I don’t like it.
23. Have a cup of tea, Dad. Thank you, Danny.
学习啦在线学习网24. Look at Eddie. He can drive a car.
学习啦在线学习网25. Listen to Alice. She can sing a song.
26. What colour are your new shorts? They are blue.
二、写出下列单词的同类词
学习啦在线学习网1. snake _______ ________ 2. summer _______ __________
3. carrot _______ _________ 4. skip ________ ___________
5. brown _______ ________ 6. soft ________ __________
学习啦在线学习网7. bus ________ ________ 8. coat _______ _________
学习啦在线学习网9. balloon _______ ________ 10. hot _______ _________
三、翻译下列词组
1. 又累又饿 _________________ 2. 蓝紫相间 _____________
学习啦在线学习网3. 一把光滑的椅子 _____________ 4. 骑车 ________________
5. 滑冰 ______________________ 6. 又软又可爱 _____________
7. 晴朗又炎热 _________________ 8. 在水里游泳 _____________
9. 放风筝 ___________________ 10. 在公园里 _____________
学习啦在线学习网11. 在夏天 ___________________ 12. 吃水果 _______________
13. 一件温暖的毛衣 ______________14. 踢足球 ________________
15. 制作小鸟 _______________ 16. 打牌 _________________
17. 跳绳 ____________________ 18. 打乒乓 _________________
19. 一幢漂亮的房子 ______________20. 打篮球 ________________
21. 一个好主意 _________________ 22. 一杯茶 ________________
23. 出去 _____________________ 24. 一个小女孩 _____________
学习啦在线学习网25. 我的爸爸 __________________ 26. 你的妈妈 _______________
27. 看着 _____________________ 28. 听着 __________________
学习啦在线学习网29. 一些色拉 _________________ 30. 三只蝴蝶 _______________
31. 一些胡萝卜 _________________ 32. 一个笔盒 _______________
学习啦在线学习网33. 鱼和肉 __________________ 34. 在儿童乐园 ______________
学习啦在线学习网四、情境说话(想一想,写一写)
1. 如何告诉别人,你喜欢跑步,不喜欢跳绳。
学习啦在线学习网2. 母亲节到了,如何向妈妈送上祝福?
3. 如何询问对方喜欢吃的食物?
学习啦在线学习网4. 如何告诉他人,你的爸爸会骑车,但不会开车。
5. 秋天到了,如何询问别人准备了什么衣服?
6. 如何告诉妈妈,你饿了,想要一些面条和肉。
7. 如何邀请你的朋友同你一起去游泳?
8. 爸爸下班回到家,你为他递上一杯茶时,该说什么?
学习啦在线学习网9. 你想知道妈妈是否会打篮球,该怎么问妈妈?
10.摸摸你的写字台,告诉大家你的感觉。
11. 过马路时,看到红灯。你会对家人说什么?
12. 如何向你的朋友介绍你所喜欢的季节及理由。
小学二年级寒假英语练习题可打印【篇15】
正确抄写下列词组和句子,并在括号内写出中文意思。
学习啦在线学习网have a look favorite sport pass the ball
学习啦在线学习网, , , , , ,
Le t ’s go and have a look
, ,
?.根据图意完成单词。
学习啦在线学习网__wi__ b__ __t f__ __t b__ __ __
黑色
f__ __tb__ __ __ p__ __ __ p__ngˉp__ng bl__ck
?.小学生二年级英语暑假作业练习题:模仿范例写一写。例:go—going
do—______________ play—______________ run—______________
学习啦在线学习网swim—______________ pass—______________ ride—______________
come—______________ dance—______________ sing—______________
?.选择框中适当的词填空。
学习啦在线学习网have play 1. ______________basketball 2. ______________to
school
go pass 3. ______________a kite 4. ______________the ball
sing fly 5. ______________a sing 6. ______________a PE class
学习啦在线学习网1. are?they?football?playing
学习啦在线学习网__________________________________________________________.
学习啦在线学习网2. favorite?what’s?color?your
__________________________________________________________?
3. red?pink?white?make?and
学习啦在线学习网__________________________________________________________.
4. are/what/doing/they
__________________________________________________________?
?.根据问句找答句,连线即可,。
1. What do you have for lunch? ? ? Rabbit.
2. What class are you in? ? ? We have rice,meat and soup.
学习啦在线学习网3. What are they doing? ? ? I’m in Class Two, Grade Four.
学习啦在线学习网4. What’s your favorite pet? ? ? They are dancing
5. How do you go to school? ? ? By bus