I knocked on the door several times but ----- answered,so I

I knocked on the door several times but _____ answered,so I left.解析：这句话中关健词but,有转则,前面肯定句,后面应该是否定句.答案B) nobody
A) somebody B) nobody C) anybody D) everybody
The professor has given us _____ advice on how to improve our memory.解析：advice是不可数名词,常见词组：give sb some advice ,因此答案：A) much
A) much B) many C) a lot D) several