How do people dobird-watching —Sometimes they______the birdsquietly, sometimes they use telescopes.

I have a bad toothache. -____

Are your parents ______ you—- Sometimes they are. For example, I have to be back home before 7 o’clock every evening.

You _____ to the meeting tomorrow if you havesomething important to do.

It’s our duty ________our city clean and beautiful.—Yes. We should do something for it.