The teacher had a _______ look when he found that none of his students had finished his homework.

—Do you like to go to a movie or walk in the country this Sunday?—I’d like the          choice. I need some fresh air.

You forgot to go to the meeting? You _____ important things. It’s so_______.

Water can absorb and give off a lot of heat without big changes in temperature,thus creating a___environment.

I am very ____________ about expressing my opinions in public in case I may make mistakes.