Many parents now remember the teacher's E-mail address and the school's website because ______. A: by doing so they needn't go to the store to buy stationery for their children B: they can reach their children's school and the teachers without traveling there C: the E-mail and the website can help them find out what their children do D: they can observe how the Internet affect their children's education every day

Mr. and Mrs. Harper are so excited today, for they have bought ______ for their new house. A: many furnitures B: many piece of furniture C: a few of furnitures D: a lot of furniture

Which is not suitable for the blank in the sentence "The store sells all kinds of rulers,______ " A: [A] so I bought some B: [B] so I bought ones C: [C] but I don't like any D: [D] and I bought medium ones

There are so many ______ in the dormitory, so I have to study in the library in the weekend.

Please identify the cause in each of the following situation. In recent decades, many people have poured into the cities and the cities have grown so large that now about 50% of the Earth's population lives in urban areas. A: The cities have grown so large. B: Many people have poured into the cities. C: Now about 50% of the Earth's population lives in urban areas. D: None of them.