1、This is (D./) interesting.
这个很有趣.
因为后面只有形容词作表语,没有名词,所以不用填冠词来修饰.
2、-- Do you often (D.here from)your American friend?
-- Yes,I do.He writes a letter to me every week.
你经常收到美国朋友的来信吗?是的,他每周写一封.
hear from sb,收到某人的来信.
3、She lives in Beijing (C.with)her parents.
她和父母一起住在北京.
with sb,和某人一起.