I.单项选择。（30分）
( )1.Linda was just going out shopping ______ the telephone rang.
A. while B. when C. after D. because
( )2.I met Mr Green ________ I was walking across the bridge, but I didn’t say hello to him.
A. before B. after C. until D. while
( )3.When his mother got home, Jimmy ________ the toys together busily.
A. put B. was putting C. puts D. to put
