3.Waste paper ________________ (should throw) in the litter bins.4.Plates and dishes _______________ (not wash) after supper yesterday.6.____________ the box _____________ (may open) now,sir?
问题描述：
3.Waste paper ________________ (should throw) in the litter bins.
4.Plates and dishes _______________ (not wash) after supper yesterday.
6.____________ the box _____________ (may open) now,sir?
答
3.should be thrown 4.were not washed 6.May be opened