Question

Our math teacher __________ in our school for 20 years and he __________ here when he was 23 years old．

1. A.
   has taught, has come
2. B.
   taught, comes
3. C.
   taught, came
4. D.
   has taught, came

Answer 1

D
解析：
考查动词的时态。for 20 year是现在完成时的时间标志。因此第一空要填has taught；后半句时间状语是when he was 23 years old，动词用一般过去时，因此天came．故答案为D。