问题

._________ it was to become was a mystery until the dust began to slowly combine into a ball moving around the sun.

A:That
B:What
C:Which
D:Whether

正确答案是：

同类题型

Why did you take a taxi____you could comehere by bus

The river is too wide for the swimmers________.

That art center is ____ used to be a factory,_____ millions of cars were made．

The form cannot be signed by anyone _____ yourself.

Linda made great progress inher English last term. — ____________.