I don’t like science _______ it’s difficult.
You will fail the English exam ________ you study hard.
Jim doesn’t study physics well.-----__________
They are late. The film __________ for five minutes.
Mr. Green _______ to Beijing two weeks ago. He ______ there many times.
-----What’s the population_______the U.S.A.? ----- the U.S.A.has _______population of 297 million.A. of, a B. of, / C. in, a D.in, /