—How long can I ______ the book, Mr. Black? — Two weeks.
It was really helpful him to take the cat to the animal centre a rainy night.
I haven’t seen Li Hong for a long time. I don’t know ______.
—Ann has finished her homework, hasn’t she?—Yes. She _____ it an hour ago.
—Is your brother at home?—No. He ________ the library. He hasn’t come back yet.
We know that about seventy percent _____ the earth _____ covered by water.