Раскройте скобки,употребляя требуюшуюся форму инфинитива 1.He knows mathematics much better than he did last year.He must (to work)a lot in summer.2.Your mathematics is very poor.You must(to work) at it in summer.3.Where is Peter?-Oh,he must(to read) in the library.He is getting ready for a very difficult examination.4.You must(to study) English for several years already.Your language is very good.5.Oh,look how white and clean everything is!It must (to snow) at night.6.Oh,you are all in snow,you look like a snowman.It must(to snow) heavily.7.Look,what huge snowdrefts yhere are everywhere,and the path is covered with knee-deep snow.It must (to snow) for several hours already.8.You look fresh!You must (to have) a good sleep at night.9.9You look very tired.You must (to have) a good sleep at night

He knows mathematics much better than he did last year.He must  work a lot in summer.2.Your mathematics is very poor.You must to work at it in summer.3.Where is Peter?-Oh,he must read in the library.He is getting ready for a very difficult examination.4.You must to study English for several years already.Your language is very good.5.Oh,look how white and clean everything is!It must to snow at night.6.Oh,you are all in snow,you look like a snowman.It must  snow heavily.7.Look,what huge snowdrefts yhere are everywhere,and the path is covered with knee-deep snow.It must to snow for several hours already.8.You look fresh!You must  have a good sleep at night.9.9You look very tired.You must have a good sleep at night