In the past few years, Chinese scientists ________ great success in the field of space flight.

1. A.
   achieved
2. B.
   have achieved
3. C.
   won
4. D.
   had won

In the past few years, Chinese scientists ________ great success in the field of space flight.

A. achieved      B. have achieved     C. won            D. had won

In the past few years, Chinese scientists ________ great success in the field of space flight.