Loại polime nào sau đây không chứa nguyên tử nitơ trong mạch polime?

A. Tơ olon.

B. Tơ lapsan.

C. Tơ nilon-6,6.

D. Protein.

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.

Kevin put a fence so that people didn’t walk on his garden

A. Kevin put a fence because he wants to remind people to walk on his garden.

B. Kevin put a fence to prevent people from walking on his garden.

C. In order to tell people to walk on his garden, Kevin put a fence.

D. So as to encourage people to walk on his garden, Kevin put a fence.

Polime nào sau đây có chứa vòng benzen trong phân tử và được dùng để sản xuất vật liệu có tính đàn hồi?

A. Poliisopren.

B. Poli(etylen terephtalat).

C. Poli(phenol fomanđehit).

D. Polistiren.