I missed the first part of ________ film Avatar.–- What a pity ! You should be here half _______ hour earlier.

Do you like the Moonlight Sonata ？—Sure , it sounds really ________.

Each year __________ fishes are killed by the polluted water and many people are made sick by the polluted air .—-So we should do something to stop it .

Look at the sign! —Oh, I see.We _______ waste water.

I think ______ necessary ______ to take more exercise.