1 . It is the silk _______ the spiders make their webs with _______ is stronger than steel.

A．which; that

B．what; that

C．that; which

D．which; which

2 . _______ that the trade between the two countries reached its highest point.

A．During the 1960s	B．In the 1960
C．It was in the 1960s	D．It was the 1960

4 . It is science married with liberal arts ________ produces us the result that makes our heart sing.

A．which

B．that

C．/

D．and

5 . ________ the mud and soil have been moved away ________ firemen can save the people in the ruins.

A．It is only then; that	B．It is only when; that
C．It is; that	D．It is if; when

6 . _______ was because the water had risen that they could not cross the river.

A．It

B．There

C．That

D．This

8 . It was on his way home ________ he ________ his wallet. The next morning he found it ________.

A．that; lost; missing	B．where; missing; lost
C．which; missed; lost	D．that; lost; missed

9 . Ironically, ______ was due to the old man’s help ______ the butterfly spent the rest of its life crawling around and never was able to fly.

A．it; which

B．that; that

C．it; that

D．that; which