1 . I had to catch my flight. That was ________ I left Tom’s party so early yesterday.

A．what

B．how

C．why

D．when

2 . The great thing about music is ______________ it can bring people of different cultural backgrounds together.

A．which	B．what
C．that	D．whether

3 . The most unforgettable moment for me was _____ I graduated from high school.

A．when

B．where

C．how

D．why

4 . They have leading experts in this field, and that’s ____ they’ve made important progress.

A．where

B．why

C．whether

D．who

5 . —Are you a native of this town?
—I was born in New York, but this is ______________ I grew up.

A．that	B．what
C．when	D．where

6 . After the earthquake, it seemed ________ the world was at an end.

A．as for

B．even then

C．even if

D．as if

7 . They have leading experts in this field，and that's __________ they've made important progress．

A．where	B．why
C．whether	D．who

8 . The world is not always ______we wish it to be.

A．that	B．which
C．what	D．where

9 . (2016·北京)The most pleasant thing of the rainy season is _____________ one can be entirely free from dust.

A．what	B．that
C．whether	D．why

10 . Tom’s most positive quality is _____ he’s very outgoing.

A．that	B．why
C．how	D．whether