The teachers are, at the moment, trying their best ______ all the necessary that their students may need for their critical examination while, sadly, some do not seem to appreciate that

A. to prepare

B. prepared

C. preparing

D. prepare

Polietilen là sản phẩm của phản ứng trùng hợp

A. CH₂=CH-Cl.

B. CH₂=CH₂.

C. CH₂=CH-CH=CH₂.

D. CH₂=CH-CH₃.

1. Hoa had a medical check-up yesterday.

2. She filled in the medical record and waited in the waiting room.

3. The doctor examined Hoa.

4. The doctor asked Hoa a few question.

5. No, it wasn't.

6. She felt very happy when she left the office.