单项选择(每题1分)
We must think twice _____ we make the final decision.
A.when | B.while | C.until | D.before |
It is pretty well understood __________controls the flow of carbon dioxide in and out the atmosphere today.
A.that | B.when | C.what | D.how |
____is certain is ___prevention is more important than treatment .
A.It;that ![]() |
B.What;that | C.As;what | D.What;what |
_______has recently been done to provide more buses for the people ,a shortage of public vehicles remains a serious problem .
A.That | B.What | C.In spite of what | D.Though what |
The experience of the Chinese nation attests to a truth____ a nation loses in times of disaster will be made up for by her progress
A.that what | B.what | C.that | D.what that |
In his speech, Premier Wen Jiabao points out that creativity is ______it takes to keep a nation highly competitive .
A.how | B.what | C.which | D.that |