When the Greeks had _____ the Persians, a soldier ran from Marathon to Athens.

There are some health problems that, when ____ in time, can become bigger ones later on.

We failed in the singing competition.– ______ . Better times are waiting for you.

Listen! There is a knock on the door.Who _____ it be?—It must be Jack.Just now I sent for him. [ ]

The social worker spent nearly two hours the plan. He said he would discuss with you about it these two days.— Really is fine.