Nobody knows for sure what effect global warming has ___ our environment in the long term

It has been announced recently that all the schools in our country ______ not have students attend school at weekends.[ ]

To tell the truth, I would rather that I ____ the pain instead of youYou don’t know how worried I was

When you read a book, you should make a mark ______ you have any question.

If he ______ more carefully, that accident _______ and he _______ .[ ]