The price of oil is much _____________ than before so that many people go to work by bus instead．

This is one of the oldest trees in theworld_____ such a big tree

I don’t think students should be allowed to do homework with friends.— I ______ you, although they often talk with each other instead of studying,.

You can’t answer my questions about internationalcharities, can you?—- ___________. I know very __________ about them.

Teachers should _____ fundamentals and difficult points in order to enable students toacquire newmaterial. [ ]