Most environmental problems exist because adequate measures for preventing them ____in the past.
— Mr. Wang, I got zero on Answering Sheet One. Could you help me correct it?— I’m sorry, but it ______ be marked by the machine. Mark your test number with a pencil 2B next time.
I’m glad to see your health ______ after the operation.
“I have to go,” she said, and with ______ she hung up the phone.
Michael knew he would certainly get ______ if he was late home.
The rising house price has become the biggest ______ of the ordinary people in China today.