怎么判断when后面用is/are还是do/does如题

怎么判断when后面用is/are还是do/does如题 只有复数形式的名词单数时后面用is还是areYour trousers( )dirty,you must have ( )washed.A.is,it B.are,it C.are ,them D.is,them像这种题怎么选择用IS还是are. The Smiths后面用is还是are few.people后面用is还是are Two days 后面用is还是are? everything后面应该用is还是are? where and when 后面接is 还是are ?when and where to build the new factory ( ) yet. A.is not decided B.are not decided C.has not decided D.have not decided two nouths后面用is还是aretwo mouths ----- quite a long time A be B are C is D was the moment后面到底跟that还是when?有时候跟that还可以省略,有时候跟when?怎么判断呢? We think they are going to work in a factory,______?A don’we B aren’t they Cdon’t they D are 到底看 We 还是 they 怎么判断 ?后面的动词要选哪个怎么判断 human being 后面用are还是is human呢? large amounts of money后面用is还是are some water后面是用is还是are? more than a child 后面用is还是are?rt More than a dozen students 后面用is还是are? one percent of 10 sheep 后面用is 还是are? each of boys后面用is还是are? there和here后面用is还是are?(>_