You promised your friend a letter; youought to ______ days ago.

How are you prepared for the new project —We have done much but a lot of equipment ______.

I can’t repair your bike until tomorrow, I’m afraid.—That’s OK, there’s _________.

The students _______ their homework carefully when the teacher walked into the classroom quietly.

Sorry, sir. I made a mistake again.—_________. Practice more and you will do better.