Cho phản ứng giữa buta-1,3-đien và HBr ở -80°C (tỉ lệ mol 1:1), thu được sản phẩm chính là

A. CH₃CHBrCH=CH₂

B. CH₃CH=CHCH₂Br

C. CH₂BrCH₂CH=CH₂

D. CH₃CH=CBrCH₃

If you had taken my advice, you _______ in such difficulties now.

A. wouldn't have been

B. hadn't been      

C. wouldn't be      

D. won't be

Kết luận nào sau đây là đúng?

A. Ankađien có công thức phân tử dạng C_nH_2n-2

B. Các hiđrocacbon có công thức phân tử dạng C_nH_2n-2 đều thuộc loại ankađien

C. Ankađien không có đồng phân hình học

D. Ankađien phân tử khối lớn không tác dụng với brom (trong dung dịch)

This room_________since the last time I was here.

A. has painted

B.has been painted

C.painted

D. had been painted

Mark the letter A, B, C, or D on your answer sheet to indicate the sentence that is closest in meaning to each of the following questions.

We couldn't solve the problem until our teacher arrived.

A. Not until we solved the problem could our teacher arrive

B. When our teacher arrived, we solved the problem

C. Until our teacher arrived, we were able to solve the problem

D. Not until our teacher arrived could we solve the problem

These school-leavers are looking forward ____ on campus

A. living               

B. to live              

C. . live                

D. to living

Thuỷ phân C₂H₅COOCH=CH₂ trong môi trường axit tạo thành những sản phẩm là

A. C₂H₅COOH; CH₂=CH-OH

B. C₂H₅COOH; CH₃CHO

C. C₂H₅COOH; HCHO

D. C₂H₅COOH; C₂H₅OH.

Choose the best answer for each of the following sentences
Larry was so……..in his novel that he forgot about his dinner cooking in the oven.

A. absorbed

B. attracted

C. drawn

D. obliged

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate thecorrect word or phrase that best fits each of the numbered blanks.

Education is more important today than ever before. It helps people acquire the skills they need for such everyday  (1)_______  as reading a newspaper or managing their money. It also gives them the specialized training they may need to  (2)_______ for a job or career. For example, a person must meet certain educational requirements and obtain a  (3)_______  or certificate before he can practice law or medicine. Many fields, like computer operation or police work,  (4)_______  satisfactory completion of special training courses.

Education is also important  (5)_______  it helps people get more out of life. It increases their knowledge and understanding of the world. It helps them acquire the skills that make life more interesting and enjoyable,  (6)_______  the skills needed to participate in a sport, paint a picture, or play a musical  (7)_______ . Such education becomes  (8)_______  important as people gain more and more leisure time.

Education also helps people adjust to change. This habit has become necessary because social changes today take place with increasing speed and  (9)_______  the lives of more and more people. Education can help a person understand these changes and provide him  (10)_______  the skills for adjusting to them.

Điền vào ô 9

A. effect      

B. affect                

C. affective           

D. effective

Cho dãy các chất: Ca₃(PO₄)₂, BaSO₄, KNO₃, CuO, Cr(OH)₃, AgCl và BaCO₃. Số chất trong dãy không tan trong dung dịch HNO₃ loãng là

A. 1

B. 2.

C. 4

D. 3.