Question

We had planted three thousand trees ________ the end of March．

1. A.
   by
2. B.
   in
3. C.
   at
4. D.
   to

Answer 1

A
根据题意“到三月底，我们已经栽了3000棵树”。根据题干中的过去完成时，应判断用短语by the end of。