A、Love. B、Conflict. C、Violence. D、Mystery. B短文说，不同的电影都有一个共同点——矛盾冲突。所以B正确。选项是名词，一般问细节或主旨。听到conflict时记录common。mysteries和love是并列出现的

Hollywood produces many different kinds of films, including mysteries, musicals, love stories and horror films. Different these films may be, they generally have one thing in common—conflict. The main character wants something very badly and will do anything to get it. The opponent tries to stop the main character from achieving his goal. This opposition creates conflict and conflict is the heart of drama. To give an example, let’s say the main character is a young man of humble origin, who wants to marry the beautiful daughter of a rich banker. The father thinks the young man is unworthy of his daughter and does not allow her to see him. The young man, who is very much in love, refuses to give up without a fight. The conflict between the young man and the girl’s father is what makes the story interesting. It forces the main characters to take action and through their action we see them as they really are. [20]In a good story, the main character changes. He is not the same at the end of the story as he was at the beginning. He learns something from his experiences. That makes him a different, perhaps a better person. And we learn something from watching him.
     [21]Good movies not only entertain us, they also help us understand a little more about life.
19. What is common to all the films produced in Hollywood?
20. What usually happens to the main character in a good story?
21. According to the speaker, what can we get from good movies?