英语冠词问题求解答

英语冠词问题求解答
1. It is widely accepted that _____ air pollution may do such _____ great damage to health that everyone should do their bit to protect the environment.
A. /; aB. the; /C. /; /D. the; a
求解释这道题为什么选D不选C?选D怎么解释?
2. ---What about _____ concert you attended last night?
---To tell the truth, it was too boring, you know, _____concert like that.
A. the; theB. the; aC. a; theD. the;不填
求解释这道题为什么选B不选A?选B怎么解释?
3.
---____ Mr. Whitewas appointed director of our department.

---Then we have two Whites now including _____ Mr. White,the doorkeeper.
A. The; aB. A; theC. A;不填D.不填; a
求解释这道题为什么选C不选B,第二个空难道不是表示特指吗?