Even the simplest everyday activities can make a real difference _____ the environment.[ ]

I rang you at about ten o’clock, but there was no reply. – Oh, that was probably ________ I was seeing the doctor.

When you have borrowed a book from the library, you should keep it well, as if it were ______ of ______.

I’m sorry I can’t stop with you. I have much work to do.

If you _________ your name on the paper, you can get a magazine.