1 . The sports meeting will be postponed until June 2^nd, _________all the people are available.

A．which

B．whose

C．when

D．that

2 . Mr. Smith owned this oil painting until the early 1990s, ________ he gave it to his grandson.

A．where

B．when

C．as

D．so

4 . We will put off the picnic until next week, ________ the weather may be better. (用适当的词填空)

5 . The human has entered the AI era, ________ robots are used in ordinary life, bringing great convenience to people. (用适当的词填空)

6 . We will put off the picnic in the park until next week, ________ the weather may be better.

A．that	B．where
C．which	D．when