It is necessary that the students ____ more excercises to do.
A
【句意】学生们有必要做更多的练习。
【难点】虚拟语气可以用于主语从句中，常用的句型为：It+is(was)+形容词that…，主语从句中的谓语用(should)+v.的表达形式。
One of the requirements for a fire is that the material ____to its burning temperature.
____,sheledalifeofcompleteseclusion.
We all found_____ to play the game.
Mrs.Whitehas_____thatsheisnotabletogetajob.
You ’d better sing. It doesn’t ______ whether you can sing well or not.