—What courses are you going to learn next term?—I don't know.But it's about time ________ on something.
Some of the doctors are paid almost ______ as the nurses.
. The government has to close those small factories to prevent the water of the river ______.
If you keep on, you will succeed ________.
—________ you__________ the editor at the airport? —No, when we got there, he___________ driven away.
Does the way you thought of___________ water clean make any sense?