In the past decades, sea ice ______ in the Arctic as a result of global warming.
| A．had melted | B．has been melting | C．melted | D．is melting |
Only when_______ 30 years old ______ to learn English.
| A．was he; did he begin | B．he was; he began |
| C．was he; he began | D．he was; did he begin |
All of us know that China has thousands of islands, _____ is Taiwan.
| A．the largest of which | B．the largest of them |
| C．the largest one | D．one of the largest |
The politician was deeply hurt when many of his former support voted _______ him and he lost his place in the government.
| A．for | B．to | C．against | D．at |
Jack wasn’t saying anything，but the teacher smiled at him________he had done something very clever.
| A．as if | B．in case | C．while | D．though |
The time he has devoted in the past 10 years________ the disabled is now considered________ of great value.
| A．to help；being | B．to helping；to be |
| C．to help；to be | D．helping；being |