Question

The Bunsen Burner is so named because it is thought ___________ by Robert Bunsen.

  A. to be invented               B. having been invented

  C. invented                     D. to have been invented

Answer 1

D

解析:

本句考查動(dòng)詞的被動(dòng)語態(tài)和時(shí)態(tài)，it+is+動(dòng)詞ed形式，to do是固定的搭配用法。而Bunsen Burner的發(fā)明是過去發(fā)生的動(dòng)作，所以用完成時(shí)態(tài)。