Để phân biệt ba chất: CH₃COOH, CH₃CH₂NH₂ và H₂N-CH₂-COOH chỉ cần dùng thuốc thử nào sau đây?

A. dung dịch HCl

B. dung dịch NaOH

C. dung dịch quỳ tím

D. dung dịch phenolphtalein.

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

TATTOOING: AN ANCIENT TRADITION

Tattooing is an old art. In ancient Greece, people who had tattoos were regarded as members of the (16) __________ classes. On the other hand, tattooing was (17) __________ in Europe by the early Christians, who thought that it was a sinful thing to (18) __________. It was not until the late 18^th century, when Captain Cook saw South Sea Islander decorating their bodies with tattoos that attitudes began to change. Sailors came back from these islands with pictures of Christ on their backs and from then on, tattooing (19) __________ in popularity. A survey by the French army in 1881 (20) __________ that among the 387 men (21) __________there were 1,333 designs.

Nowadays, not everybody finds tattoos acceptable. Some people thing that getting one is silly because tattoos are more or less permanent. There is also some (22)  __________ about (23) __________ a blood disease from unsterilized needles. Even for those who do want a tattoo, the (24) __________ of getting one is not painless, but the final result, in their eyes, is (25) __________ the pain.Question 18

A. be

B. create

C. do

D. make

Poli(etylen terephtalat) được điều chế bằng phản ứng với axit teraphtalic với chất nào sau đây?

A. Etilen

B. Etylen glicol

C. Glixerol

D. Ancol etylic