27.It is necessary that everything ____ ready by 6:00 p.m.A.be B.will be C.shall D.would be 选哪个,为什么?

if it is necessary /if necessary /when it is necessary 意思一样吗 i don't think it is necessary.(同义句）i think____ _____.(句型转换） when it is necessary 为什么可以变为when necessary? it is necessary for you to work Is it necessary to learn grammer It is necessary for sb to early 是什么副词It is certainly necessary! It is necessary to do 的例句 we havent settled the problem 什么什么 it is necessary for him to study abroadA,if Bwhere Cwhether Dthat if you don't want to get into trouble .say no without hesition when it is necessary 为什么可以省略IS?Do you think it necessary to...是不是少了个is?那I don’t think it is necessary to leave so early.是对还是错？ i feel it necessary 的句子成分分析下为啥不是 it is necessary 关于necessary.it is necessary to do sth.it is nec关于necessary. it is necessary to do sth. it is necessary to doing sth. 两者有什么区别?什么时候用to do .什么时候用 to doing?请回答, we think that is necessary还是we think that it is necessary is it necessary to tell his father everything?此句用is that necessary Change is not necessary to life,it is life it is clear that sleeping is necessary to everyone Don' t you think it necessary ________English well?