When H7N9 bird flu first appeared, people didn't know_______ doctors could cure it.
-I like this pair of trousers a lot. Can I ________? -Yes, of course,
-Can I spend ______ minutes in bed?-Sorry, you can’t.
He always ______ as a ghost at the Halloween party
—How much _________an iphone 5_________?—More than 5000 yuan.
Look , your parents_______ you at the bus stop.