— the population of the U.S.A. in 2009?—It about 309 million.A.What is; is B.What was; wasC.How many is; was D.How many was; is
Sam spends two hours _______ his homework every day.
He is ill. I don’t know _______ he will come to school.
—_______ do you prefer, walking or running? —I like running better.
I see Wei Han _______ English almost every morning.
I want to be a doctor when I .