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

—You can't imagine ________ fantastic fun online chatting is.

—Really？But it may cause a lot of trouble sometimes.

A．what A B．how C．why D．so

________ made the school proud was ________ more than 90% of the students had been admitted to key universities.

A．What；because B．What；that

C．That；what D．That；because

It is generally considered unwise to give a child ________ he or she wants.

A．however B．whatever C．whichever D．whenever

—I drove to Zhuhai for the air show last week.

—Is that ________ you had a few days off?

A．why B．when C．that D．where

It was a matter of ________ would take the position.

A．who B．whoever C．whom D．whomever

________ you have seen both fighters，________ will win?

A．Since；do you think who

B．As；who you think

C．When；whoever

D．Since；who do you think

China's success in manned－spacecraft travel shows ________ our country has become one of the greatest powers in space research.

A．what B．which C．/ D．it that

There is a common belief among them ________ rubbish can and should be put to good use.

A．which B．if C．whose D．that

________ has been mentioned above，continued chairman after he took a sip of coffee，________ the project must be carried out before spring flood comes.

A．As；that B．That；which

C．This；which D．It；that