A、Ask someone else. B、Skip them temporarily. C、Look at the subtitles. D、Stop and replay it. D题干询问的是人们看电影时，对某些片段感到困惑应该怎么做。短文中提到，如

Watching movies is a good way to improve your listening. I would stress the usefulness of repetition. So watch a DVD of an English-language film with Chinese subtitles. Then, a week or so later, watch the film again with the subtitles covered up. This time, you will know broadly what the characters are trying to say, which will help your brain link the English words with their meanings.(16)Of course, you can pause and rewind the film if there are certain bits that really mystify you.
     (17)The third step would be to find a way to listen to the soundtrack of the film without watching it. You should know the scenes and the story well by now, so by removing the pictures your brain will really focus on the language spoken.
     (18)Before you do any of this, think carefully about which kind of film you want to use to practice your listening. If you want to learn American English, be sure to watch a film set in the USA. If you choose a really well-regarded film, you will probably be able to buy the screenplay of the film, which will be very useful to you. Lastly, choose a film that you are not going to get tired of if you watch it three times!
    Generally speaking, don’t expect too much when it comes to listening.(19)Even native speakers miss some things when they watch movies. You should not expect to ever understand everything 100% .
16. What can people do while confused with certain fragments in a movie?
17. What is the third step to improve listening by watching a movie?
18. What should people do before using movies to improve listening?
19. What do we learn about the native speakers watching movies?