She has ________ good sense of humour and never says _______ bad word about anyone.

In American there are more households withpets than ______ with children.

The research on the new bird flu virus vaccine is challenging and demanding. Who do you think can do the job?—____ my students have a try?

If we want to be a _____ visitor in a foreign country, it is important to know how to ask for help ________.

They all looked ________ at the teacherwhen he told them the good news.