21. How many eggs do you need, Mom ? - ………………. A. a half dozen B. half a dozen C. a dozen half D. dozen a half 22. Hoa’s house is not near her school so she goes to school __________. A. on foot B. by bike C. by a bike D. on bus 23. There is __________ opposite the drugstore. A. the police station B. a police station C. police station D. police stations 24. What’s the time now? ~ It’s __________twelve o’clock. A. at B. nearly C. near D. most 25. __________care when you bring that dish. It’s hot. A. Be B. Have C. Make D. Take 26. Why don’t we go to the zoo? ~ __________. A. Because I’m going B. Let’s drive there C. It takes an hour D. That’s a good idea 27. Mary is the __________of the two girls. A. small B. smallest C. smaller D. smaller than 28. There is __________bread on the table. A. a B. an C. some D. many 29. How far is it from your house to school? ~ __________. A. About ten miles B. About two hours C. At 10 o’clock D. In some minutes

hệ tuần hoàn máu đi từ đâu đến đâu vậy ạ

11. _____________do you get there? – We walk, of course. A. Why B. What C. How by D. How 12. What time _____________ on television? A. is the news B. are the news C. is news D. are news 13. I am very tired. - ___________. A. Me too B. for me the same C. Also me D. I also 14. Don’t be late __________ your school. A. on B. at C. to D. for 15. The weather often ______ quickly. It is difficult to forecast. A. change B. changes C. is changing D. is going to change 16. When it becomes hot, people often feel ______ A. hungry B. thirsty C. happy D. worried 17. When you go out, please buy two ………… of soap for me. A. rods B. bars C. tubes D. bottles 18. They usually go …………. after work. A. to fishing B. to swimming C. cinema D. home 19. Everyone is having ………… at the picnic. A. good time B. good times C. the good time D. a good time 20. Do you have any toothpaste? I’d like a large….………….. A. box B. bar C. tube D. packet

hỗn hợp khí sau hỗn hợp X gồm 2a mol H2 và a mol khí CO2, hỗn hợp Y gồm 3b mol khí H2 và 2b mol SO2, hỗn hợp Z gồm 3c mol khí CO2 và 8c mol khí N2 .tính tỉ khối của hỗn hợp khí trên so với không khí. help me!

Choose the best answer from A, B, C or D to complete each of the following sentences. 1. What would you like …………………dinner? A. with B. at C. for D. of 2. We are going to have an English examination ………………… April, 21st . A. on B. to C. at D. in 3. …………………are a sandwich and an ice-cream? -They’re two thousand dong. A. How many B. How much C. What D. Where 4. I eat an apple every morning. It’s my…………………fruit. A. good B. like C. favorite D. cold 5. …………………is your uncle going to stay here? - ……………… about three days. A. How long - For B. How far - For C. How long - At D. How long - From 6. ..........................do you do when it’s hot? - I go swimming A. Who B. What C. When D. Where 7. I want a good pair of shoes because I always goes …………………in the morning. A. sailing B. swimming C. jogging D. fishing 8. Ho Chi Minh city is .....................city in Viet Nam. A. big B. bigger C. the big D. the biggest 9. Why don’t we go to the zoo this Sunday morning? A. You are well B. Because I don’t like animals C. That’s a good idea D. Thanks a lot 10. Is her face round………………… oval? A. and B. or C. but D. of

TÌm tất cả các đa thức f(x) có các hệ số nguyên thõa mãn điều kiện : (x+1).f(x)=(x-2).f(x+2) và f(0)=1

tìm số nguyên x,y biết (2x+1)(y-3)=2

Giải bài toán sau: Tỉ số của hai số a và b bằng 34. Tìm hai số đó, biết rằng a - b =5.

CHo tam giác ABC vuông tại A có đường phân giác BD . Kẻ đường thẳng DH vuông góc với BC tại H . Trên tia đối của tia AB lấy K sao cho AK = CH . a)CMR : 3 điểm H,D,K thằng hàng b) CMR : 2(AD+AK)>CK

Điền một từ thích hợp vào mỗi chỗ trống trong đoạn văn sau. There are four (1)………………………in a year in our country. They are spring, summer, fall (2)………………….. winter. In the spring, the (3)…………………………is usually warm. Sometimes it is cold, but not (4)………………………..cold. There are many flowers in this season. (5)………………………..spring, it is the summer. In the summer, the days are long and the (6)…………………….are short. We often go on (7)…………………. in the summer. (8)……………………….is a nice season. The weather is often cool. In the winter, (9)…………………….usually very cold. The days are short and the nights are long. We always wear warm (10)………………………in the winter.