The bright flowers and warm winds______that spring was here.

I found _____ necessary to save energy and protect the environment.

下列各句中，没有语病的一项是（ ）

Can I get out at noon?—No. The school rules state that no student _____be allowed out at lunchtime, unless he has a request form.[ ]

.I think _________ of the materials Ilistened to at the beginning of the exam ____ easy.