He is very ________today. Look, he is laughing _________.

Eric, are your parents angry about your English in this exam?—Oh, of them is angry. They just told me to get better grades next time.

The telephone_____talking to prople far away.

Some researchers believe that there is no doubt ____ a cure for AIDS will be found.

Paul is very proud ______ his father because he helps keep our city beautiful. [ ]