Question

【题目】Jack ___________a few discoveries in chemistry since he became a scientist.

A.is makingB.will makeC.madeD.has made

Answer 1

【答案】D

【解析】

句意：杰克自从成为科学家以来，在化学方面有了一些发现。

考查时态。is making现在进行时；will make一般将来时；made一般过去时；has made现在完成时；根据“since he became a scientist”，所以此处用现在完成时，故选D。