—How’s your tour around the North Lake? Is it beautiful?—It __________ be, but it is now heavily polluted.
What great trouble the boy _____his father to give up smoking!
“I called you yesterday. A woman answered, but I didn’t recognize her voice.” “Oh, it _____ my aunt Jean.”
Anyone _______ bags, boxes, or whatever, was stopped by the police.
---Why did the policeman question Tom?---He was ________of taking part in the killing.
______ the teacher has given permission, ______allowed to use the equipment in the lab.