Mr. Black is a careful and experienfed engineer so he is often to finish some challengin

问题补充：

Mr. Black is a careful and experienfed engineer, so he is often to finish some challenging tasks.

A. appreciated

B. approached

C. appointed

D. agreed

答案：

A. appreciated

B. approached

(答案→)C. appointed

D. agreed

解析：动词用法。A欣赏；B靠近；C任命；D同意；Appoint sb to do sth…任命某人做某事…；句意：布莱克先生是一个细心有经验的工程师，所以他经常被任命去完成一些有挑战性的任务。