价格的变动会对我们的生产和生活产生重要的影响。某一商品价格提高,可能会使这种商品的( )①需求量减少 ②供给量增加③替代商品的需求量增加 ④互补商品需求量减少②③④ B.①②③ C.①②④ D.①②③④
—I’m sorry I have failed again in the math exam. — _________ ? You’ve been working hard at the subject.
—I really don’t know how to thank you enough. —.
On our way to school, suddenly it began to rain, and we hurried to take______under a big tree.
I can still remember that it is since the 1990’s, _____ we began to use cell phones,_______ the number of mobile users has greatly increased.
—I can never forget the day ___ we spent together in the summer camp. —Well, especially the day _______it suddenly began to rain in the middle of the night.