They all looked ________ at the teacher when he told them the good news.
He found ____ very difficult _____ the problem.
—Which sweater can you choose, the blue one or the red one?—____ is OK, I think. Both go well with my trousers.
Many more trees should ____ this year.
—____ the workers are very tired, ____they keep on working.— They are great. We must learn from them.
If Tony_____ to the corner this weekend, Bob will join him.