题目内容

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

 

D

本句考查动词的被动语态和时态,it+is+动词ed形式,to do是固定的搭配用法。而Bunsen Burner的发明是过去发生的动作,所以用完成时态。

练习册系列答案
相关题目

违法和不良信息举报电话:027-86699610 举报邮箱:58377363@163.com

精英家教网