—What’s up? You look down. —I have piles of papers ________, but I type so slowly.
There is no doubt _______ my friend is not satisfied with what they have done.
We should learn from those _____ are always ready to help others.
Friends should be_____ about each other’s feelings.
He _____ a Party member last year.
Professor Smith, along with his assistants, _____on the project day and night to meet the deadline.