He speaks English so well that he is thought of as a(n) ____ speaker.
| A．determined | B．native | C．official | D．loose |
Between the two generations, it is often their different views of life and value _______ cause family conflicts．
| A．which | B．what | C．that | D．who |
_________ a certain doubt among the people as to the practical value of the project．
| A．It has | B．It remains | C．They have | D．There remains |
The hours ________ the children spend in their one way relationship with television people undoubtedly affect their relationships with real-life people．
| A．that | B．when | C．in which | D．on which |
Low-carbon lifestyle is of great benefit to improve the world environment, but the problem is difficult to _________．
| A．solve | B．be solved | C．solve with | D．solving |
After ten years abroad, he still recognized his old colleagues ________ he set foot in China．
| A．immediately | B．for the first time |
| C．while | D．moment |