问题

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
B:having been invented
C:invented
D:to have been invented
正确答案是:
同类题型
It’s ten o’clock. Betty _______ piano.
I want to buy a dictionary .But I have ______my money .
I’ve finished my homework, Tony.—_______.
______ is no doubt that the Rockets will defeat the Washington Wizards in the nextgame.
Maybe the disaster can destroy our homes, but_______can destroy the love in our people.