Mary _________ as a volunteer teacher for 10 years.

The old man feels very _________because all his children have gone abroad and his wife _________ for almost two years.

What do you think of the NBA basketball match last night?–It was__，I really enjoyed it.

The man in front of me came to _______a sudden stop ______I almost ran into him.

If you don’t know how to use the word, you should _________ in a dictionary.