我觉得第一句回答要点是地点,第二句是动作。可以简单地将go to school理解成做一件事,将go to the school理解成去一处地方,第一个school为事件概念,第二个位空间概念,同样思路,in hospital和in the hospital表达两个不同的意思,如二楼所说。提醒一句,不管用不用the,英语本族人都很少回答说“I'm going to (the) school”,因为这很啰嗦,很不自然,有点像在背教科书。一般他们只说“To (the) school”就行了,故上面两问题的回答分别是:1.——Where are you going? ——To the school/ the museum/ the library.2.——What are you going to do? ——To school/ dance/ swim/...