Vận tốc truyền âm thanh trong nước là 1500m/s . Một người ngâm trong nước và nói to cho người đứng sát mặt nước cách mặt nước 3470m. Hỏi sau bao lâu người đó nghe được tiếng nói

Biết khoảng cách từ nơi mình đứng đến chỗ sét đánh là 2210m. Biết rằng vận tốc truyền âm thanh trong không khí là 340m/s.thì thời gian nghe thấy tiếng sét là bao nhiêu từ khi thấy chớp

A: How many hours a week do you usually work? B: …………..………………….…………… A: Why doesn’t Nam want to go to the park? B: ……………..…………………………..……… 3. A: What time does your sister get up every day? B: ……………………………………… 4. A: Would you like to play basketball? B: ……………………………………………. 5. A: Let’s play some computer games. B: ……………………………………………………. 6. A: What do you usually do after school? B: ……………………………………………………..

1. A: How many hours a week do you usually work? B: …………..………………….…………… (2.5 Điểm) Once a week Three times a week Thirty hours a week Twice a week 2. A: Why doesn’t Nam want to go to the park? B: ……………..…………………………..……… (2.5 Điểm) Because it’s so great. Because it’s very fun. Because it’s interesting. Because it’s raining. 3. A: What time does your sister get up every day? B: ……………………………………… (2.5 Điểm) At 7:00 From morning till night In the morning It’s 6:30 4. A: Would you like to play basketball? B: ……………………………………………. (2.5 Điểm) I’d love to. You’re welcome. Yes, I do. No, I don’t. 5. A: Let’s play some computer games. B: ……………………………………………………. (2.5 Điểm) Yes, we do. Good job! Come on! Sorry. I have too many assignments. 6. A: What do you usually do after school? B: …………………………………………………….. (2.5 Điểm) I’m good at playing soccer. I don’t like playing soccer. I usually play soccer once a week. I play soccer with my friends.

IV. Supply the correct form of words in the brackets. HCM City is (big)........................................... city in Vietnam. Motorbikes are (fast) .....................................than bikes. In most countries, there are organizations for ( teen) ................................................. Her English is (good)..................................................... than my English. Vietnamese students have (few) ...........................vacations than America students. Students feel happy and (excite).......................................... during recess. In Electronics, we learn to repair (house) .................................................appliances. Mr. Tan works (many) ....................................................hours than Mr. Nam. Summer vacation is ( long).............................................. vacation of Vietnamese students. V.Complete the sentences using the words given: 1. Nam/ listen/ his portable CD player / now. ............................................................................................................................................ 2.you / usually/ talk/ friends / recess? ............................................................................................................................................ 3. Let’s / to / cafeteria / get / cold drink. ............................................................................................................................................ 4. What about / go / the zoo/ tomorrow morning? ............................................................................................................................................ 5.Talking / be / most popular / activity / recess. ............................................................................................................................................ 6. How many/ he / does / a / usually/ do / week/ homework? ............................................................................................................................................ 7.Linh/ have / Math/ Tuesday / Friday. ......................................................................................................................................... 8.Schools / Viet Nam / different / schools / USA. ............................................................................................................................................ 9.you / have / Biology books / Science books ? ........................................................................................................................................... 10.Football / the / popular / after-school activity. ........................................................................................................................................ 11.books / back / the library / in English . .......................................................................................................................................... 12. What /classes / you /have / Monday ? ....................................................................................................................................... 13. I / 14 / my / next birthday. ..................................................................................................................................... 14. you/ like / go / movies / me / tonight? ......................................................................................................................................... 15. Which/ subjects/ you /good? ......................................................................................................................................... VI. Reorder the words into complete sentence: 1. house / is / market / the / far / to / from / how / it / Trang’s? ………………………………………………………………………………………………… 2. lives / street / grandparents / he / Nguyen Du / his / on / with ………………………………………………………………………………………………… 3. Mrs / the / boy / to / who / Quyen / talking / is? ……………………………………………………………………………………………… 4. movies / go / why / to / don’t / the / we? ....................................................................................................................................... 5. goes / bus / Hoang / day / work / Mr / every / to / by ……………………………………………………………………………….……………… 6. dinner / house / you / our / like / would / come / to /for/ to? ............................................................................................................................................ 7.date / on / my / is / July 15th / birth / of . ........................................................................................................................................... 8. boring / an / movie / what! ................................................................................................................................ 9. vacation/ will / during / What / Minh / his/ do / ? / ............................................................................................................................................ 10.subject / do / which / you / best / like? ............................................................................................................................................ 11.recess / part / different / in / students / take / activities / at. ............................................................................................................................................ 12. friends / Ha Noi/ lot / does / his / Hoang / of / in / a / have? …………………………………………………………………………………………………. 13. noisy / the bell / yard / very / rings / until / the / is ………………………………………………………………………………………….…… 14. computer / use / science / class / in / Hoa / computer / a / learns / her / to ………………………………………………………………………………………………… 15. be / on / Lien / next / will / her / thirteen / birthday. ............................................................................................................................................

Cho tam giác abc vuông tại a, có ab = ac .gọi k là trung điểm của cạnh bc a) chứng minh ∆akb=∆akc b) chứng minh ak là đường trung trực của bc