Chọn đáp án đúng:

1.Landa wants.......books after dinner

A.reads B.reading C.read D.to read

2.Mary is the........of her three girls

A.small B.smallest C.smaller D.small

3.It.......me about an hour to get to work

A.gets B.makes C.spends D.takes

4.Don't forget.................the bank first thing tomorrow morning

A.to phone B.phoning C.having phoned D.to have phoned

5.Mr.Baker doesn'twant much milk in his coffee.He ask for..............

A.little B.few C.a few D.a little

Chỉ cần viết đáp án ra cũng được!

Câu này mình đã giải được một đoạn rồi nhưng khi ra 2 TH thì không biết phân tích thế nào để chọn đáp án nữa. Hoặc cũng có thể mình sai ngay từ phương pháp làm. Rất mong mọi người giúp đỡ!

Nếu có thể thì giúp mình xem luôn cách làm có gì sai không nha.

Đề bài: Cho 2 axit cacboxylic mạch hở A và B (M_A < M_B). Nếu cho hỗn hợp A và B tác dụng với Na dư được số mol H₂ bằng một nửa tổng số mol A và B trong hỗn hợp, còn nếu cho hỗn hợp A và B tác dụng với nước brom dư thấy số mol Br₂ đã phản ứng nhỏ hơn tổng số mol A và B trong hỗn hợp. Nếu trộn 20 gam dung dịch axit A nồng độ 23% với 50 gam dung dịch axit B nồng độ 20,64% được dung dịch D. Để trung hòa D cần vừa đủ 200 ml dung dịch NaOH 1,1M. Phát biểu đúng là:

A. A phải cho được phản ứng tráng gương.

B. B có đồng phân hình học.

C. A hoặc B là một trong 2 nguyên liệu để tổng hợp thủy tinh hữu cơ.

D. A, B hơn kém nhau một nguyên tử C trong phân tử.

Giải:

Vì: A, B tác dụng với Na thu số mol H₂ bằng 1 nửa tổng số mol A, B.

⇒ A, B là axit đơn chức.

Mà: A, B cộng Br₂ thì n_Br2 < n_A + n_B

⇒ A hoặc B có liên đôi C = C trong phân tử.

Gọi: \(\left\{{}\begin{matrix}n_{C_nH_{2n+1}COOH\left(A\right)}=a\left(mol\right)\\n_{C_mH_{2m-1}COOH\left(B\right)}=b\left(mol\right)\end{matrix}\right.\)

\(\left\{{}\begin{matrix}m_A=4,6\left(g\right)\Rightarrow a=\dfrac{4,6}{14n+46}\\m_B=10,32\Rightarrow b=\dfrac{10,32}{14m+44}\end{matrix}\right.\)

Mà: \(a+b=n_{NaOH}\)

\(\Rightarrow\dfrac{4,6}{14n+46}+\dfrac{10,32}{14m+44}=0,22\)

\(\Rightarrow n=\dfrac{231,84-77,28m}{43,12m-8,96}\)

Xét từng TH, ta thấy m = 2 thì n = 1 và m = 3 thì n = 0

\(\Rightarrow\left\{{}\begin{matrix}A:CH_3COOH\\B:C_2H_3COOH\end{matrix}\right.\) hoặc \(\left\{{}\begin{matrix}A:HCOOH\\B:C_3H_5COOH\end{matrix}\right.\)

Mn ơi giúp em với ạ, chọn đáp án đúng và giải thích vì sao

TEST 04

1. My sister failed the exam because she was lazy.

A. Because my sister's laziness, she failed the exam.

B. Because of my sister's laziness, she failed the exam.

C. Because of my sister was lazy, she failed the exam.

D. Because of my sister laziness, she failed the exam.

2 "What is your name?" Mary asked Tom.

A. Mary asked Tom what his name is.

B. Mary asked Tom what his name was.

C. Mary asked Tom what his name were.

D. Mary asked Tom what your name was.

3 Jack can't tell you about that sight because he doesn't see it.

A. If Jack saw that sight, he couldn't tell you about it.

B. If Jack didn't see that sight, he could tell you about it.

C. If Jack saw that sight, he could tell you about it.

D. If Jack didn't see that sight, he couldn't tell you about it.

4. He told her about the book. He liked it best.

A. He told her about the book which he liked it best.

B. He told her about the book which he liked best.

C. He told her about the book whom he liked best.

D. He told her about the book whose he liked best.

5. I always give my mother flowers on Mother's Day.

A. My mother always is given flowers on Mother's Day.

B. Flowers is always given by my mother on Mother's Day.

C. My mother is always given flowers on Mother's Day.

D. My mother is given always flowers on Mother's Day.

6. I'm looking for a job as a secretary.

A. I'm looking for someone who works as a secretary.

B. I'm trying to find a job as a secretary.

C. A secretary is looking for a job as my job.

D. I was offered a job as a secretary.

7. Mr.Richards lost his job because he was late every day.

A. If Mr.Richards were late every day, he would lose his job.

B. If Mr.Richards had been late every day, he would have lost his job.

C. If Mr.Richards weren't late every day, he wouldn't lose his job.

D. If Mr.Richards hadn't been late every day, he wouldn't have lost his job.

8. The black dress is more expensive than the white one.

A. The black dress is cheaper than the white one.

B. The black dress is not as expensive as the white one.

C The white dress is not as expensive as the black one.

D. The white dress is as expensive as the black one.

9. Although she is intelligent, she doesn't do well at school.

A. In spite of intelligent, but she doesn't do well at school

B. Despite being intelligent, she doesn't do well at school.

C. Even though her intelligence, she doesn't do well at school.

D. In spite the fact that she is intelligent, she doesn't do well at school.

10. The dictionary was so expensive that I didn't buy it.

A. The dictionary was enough expensive for me to buy.

B. The dictionary was too expensive for me to buy,

C. It was an expensive dictionary so that meant I didn't buy.

D. It was so an expensive dictionary that I didn't buy it.

11. "Don't walk on the grass", the gardener said to us.

A. The gardener said to us don't walk on the grass.

B. The gardener told us not to walk on the grass.

C. The gardener suggested us not to walk on the grass.

D. The gardener advised us not walking on the grass..

12" Do you have a camera?" she asked.

A. She wanted to know if I have a camera.

B. She wanted to know if I had a camera.

C. She asked me whether I did have a camera.

D. she asked me whether did I have a camera.

13. The exam lasted three hours.

A. We finished the exam at three o'clock.

B. We had three-hours exam.

C. It was a three-hour exam.

D. It takes us three hours to take the exam.

14. They are watering the flowers in the garden.

A. The flowers are being watered in the garden.

B. They need some water and flowers in the garden.

C. There are some water on the flowers in the garden.

D. They are putting the flowers in water in the garden.

15. Unlike her friends, Jane prefers an independent life.

A. Jane doesn't like her friends because she prefers an independent life.

B. Her friends live in an independent life and Jane doesn't like it.

C. Jane doesn't like her friends to live in a dependent life.

D. Jane prefers an independent life but her friends do not.

16. When they arrived, the good seats were already taken.

A. They didn't get good seats because they arrived too late.

B. They arrived late enough to get good seats.

C. They had to stand for a long time to have good seats.

D. They couldn't get good seats although they arrived early.

17 Keeping calm is the secret of passing the driving test.

A. Keep calm or you will pass the driving test.

B. As long as you keep calm, you will pass the driving test.

C. Unless you keep calm you will pass the driving test.

D. Pass the driving test is without keeping calm.

18 The exam was much easier than he had expected.

A. The exam was much easier that he finished it all.

B. He did not find the exam as difficult as he had thought.

C. It's possible for him to perform well on the exam.

D. He had expected that the exam was easy.

19. John and Mary have been married for five years.

A. John and Mary's marriage life lasted five years.

B. It took John and Mary five years to prepare their wedding.

C. It is five years since John and Mary got married.

D. John and Mary got married after five years of being friends.

20. "Tsunami" is a Japanese word. This word means "harbor wave".

A. "Tsunami" is a Japanese word which it means "harbor wave".

B. "Tsunami" is a Japanese word it means "harbor wave".

C. "Tsunami" is a Japanese word which means "harbor wave".

D. "Tsunami" means "harbor wave" is a Japanese word.