用情态动词填空：1.a:__I have your e-mail address,please?I want to keep in touch with you.
b:Sure.It's tomtang@hotmail
2.a:It's ten o'clock now.Turn off the lights,John.We__observe school rules.b:OK.
3.A:___ I leave early?b:Yes,of course
4.a:Look!Our classroom is very dirty.b:We___clean it after class.
5.a:Tom looks ill.b:Yes,he does.He___go on working.He___go to see the doctor.
6.a:I'm going to buy a ticket for tomorrow's film.b:No,you___.I've got two tickets.I___give you one.
7.a:San,___you help me with my English?b:Sure.What time?
8.a:___I return this magazine tomorrow?b:No,you___.You___return it to me next week.