问题

fety of gas, the government has checked the city’s gas supplysystem thoroughly.

A:To ensure
B:Ensuring
C:Having ensured
D:To have ensured

正确答案是：

同类题型

Ann is in hospital.— Oh, really? I ______ knowI ______ go and visit her

You can tell him everything，as he is a man who you can _____ on.

下列各句中没有通假字的一项是（）

They offered a lot of useful information for your report; I can understand how ________ you must be feeling to them now.

Talking with my parents is ____difficult for me. They never understand me. — Don’t worry . Nothing is difficult if you try your best.