The scientist my father works is about 50.A. on whomB. to whichC. with whichD. with wh

问题补充：

The scientist, my father works, is about 50.

A. on whom

B. to which

C. with which

D. with whom

答案：

A. on whom

B. to which

C. with which

D. with whom

解析：句意：和我爸爸一起工作的科学家大约50岁。with whom 引导定语从句，with whom 放在定语从句中即为:myfather works withtheengineer.所以选D。