1.Whenandwherhecamehere(is/has)notknownyet.2.Theydiscussed(if/whether)theycouldsettletheproblemwithouthishelp.3.Heinsistedthathewasingoodhealthand(is/be)senttoworkthere.

Question

1.When and wher he came here (is/has)not known yet.
2.They discussed (if/whether)they could settle the problem without his help.
3.He insisted that he was in good health and (is /be) sent to work there.

Answer 1

1,is ,表示被动态 就是这件事情还不被知道.
2,whether,在某些动词后(如 discuss 等) 通常只用 whether
3,be,前面那个was表示的是事实,后面选择原型是因为虚拟语气中,省略了should