1 . My father retired in 2008, _____ he has been devoting his time to gardening.

A．at which	B．since when
C．when	D．after that

2 . I didn't become a serious climber until the fifth grade, _____ I went up to rescue a kite that was stuck in the branches of a tree.

A．when	B．where
C．which	D．why

3 . Bungee jumping is an adventurous sport, popular with young adults, __________ courage matters more than strength.

A．whose	B．that
C．of which	D．where

4 . Between the two parts of the concert is an interval, ________ the audience can buy ice­cream.

A．when	B．where
C．that	D．which

5 . I walked in our garden,                  Tom and Jim were trying a big sign onto one of the trees.

A．which	B．when
C．where	D．that

6 . The Voice of China has set up a big stage for young people with a talent for music, ____ some of them have stood out among others.

A．which

B．when

C．who

D．where

7 . The book was written in 1946, ____ the education system has witnessed great changes.

A．when

B．during which

C．since then

D．since when