问题
It is not until recently ______ thescientists have found proof of there being water on Mars.
A:when
B:that
C:how
D:what
B:that
C:how
D:what
正确答案是：
同类题型
at you are in charge of the department, you are ___________ to carry out the plan.
your English is poor, why not ________ anEnglish club to improve it
_ which direction are you going,north or south–I’m heading north
Shall we meet at the station at 8 a.m–––In fact we ________.The train _______until 10 a.m.