She likes eggs, meat __________ milk, but I don't like meat, milk __________ eggs.
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.