83．He's out. He ____ the library.

　A．went to

　B．has gone to

　C．has been to

　D．had gone to

82．I've ____ this dictionary ____ a year. It's still new now.

　A．bought; for

　B．had; for

　C．bought; since

　D．had; since

81．----How long have you ____ there?

　----About four years.

　A．come

　B．gone

　C．left

　D．worked

80．His hair ____ white these days.

　A．be

　B．are

　C．has turned

79．Mrs Black is a worker of No. 1 Machine Factory. She ____ there since it opened in 1958.

　A．worked

　B．works

　C．has worked

　D．is working

78．John ____ the factory since 1984. He's one of the oldest workers here now.

　A．came to

　B．comes to

　C．has been in

　D．has come to

77．Our workshop ____ since two years gao.

　A．was open

　B．opened

　C．has been open

　D．has opened

76．My grandpa died six months ago, that is to say, he ____ for half a year.

　A．has been dead

　B．died

　C．was dead

　D．has died

75．We ____ English for three years already. And we can speak a little English now.

　A．learn

　B．have learned

　C．has learned

　D．will learned

74．I don't know when he ____ .When he ____ , I'll let you know.

　A．comes; comes

　B．will come; comes

　C．comes; will come