All happy families _____ one another, but each unhappy family is unhappy in its own way.
| A．resemble | B．are similar |
| C．similar to | D．resemble to |
Before the problem can be solved，it must be obvious ________ the problem itself is.(2011·湖南，31)
| A．what | B．that | C．which | D．why |
His writing is so confusing that it's difficult to make out ________ it is he is trying to express.(2011·安徽，33)
| A．that | B．how | C．who | D．what |
It is by no means clear ________ the president can do to end the strike.(2012·新课标全国)
| A．how | B．which | C．that | D．what |
________you said at the meeting describes a bright future for the company.
| A．When | B．How | C．What | D．That |
From space, the earth looks blue.This is ________about seventy－one percent of its surface is covered by water.
| A．why | B．how | C．because | D．whether |