完形填空。阅读下面短文，掌握其大意，然后从 21～40 各题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题纸上将该选项标号涂黑。

I was walking in my school campus from my office to my car at about 9pm. On the way, I ran into a fellow who was ____1____ lost. He asked me for directions, saying he needed to get to East Palo Alto. But the ____2_____ was that he was walking in the complete opposite direction!

I _____3____ him in the correct direction, but warned him it was a long way off. He didn't speak English very well, and generally seemed without sense of ____4_____. I quickly felt like helping him. ____5_____ he was a big guy, I got the ____6_____ that he was harmless.

I sent him on his way, and I walked away towards my car. Just as he was going out of a short way, something ____7_____ me clicked, and I offered him a ____8_____. He gratefully accepted, and he offered to show me his ID. I declined, but ____9_____ my hand and introduced myself. He said his name was Mario.

Mario followed me to my car. When I unlocked the passenger door for him, he didn't get in _____10____ I assured him it was fine. As we sat in the car together, I suddenly got ____11_____. “If this guy wanted, he could hurt me and take my car”, I ____12_____ calling my brother as a safety precaution (预防措施), but then I felt determined not to feel scared.

Mario and I got into some _____13____. He told me about his family in Mexico, how he works _____14____ doesn't ever earn enough, how he used to live near Fresno and work on the farms but now ____15_____ more in the Bay Area. It was good talking to him, though I couldn't shake the nervousness completely. I kept asking him questions that would give me clues as to ____16_____he was being truthful.

When we got into East Palo Alto, I pulled into a gas station and told him it was as far as I could take him. He quickly got out and ____17_____ me several times, saying he _____18____ find his way home from there.

Thinking back on it, I am glad to give a ride to Mario. Although it was risky, I think such things should be done without _____19____, or not at all. I wouldn't say I'd _____20____ a hitchhiker（搭车人）again, but I know that if I did, I would make sure I could offer more love and less fear.　　

1. A. eventually           B. obviously                C. naturally          D. casually

2. A. problem               B. chance                           C. cause            D. effect

3. A. approved          B. expressed                C. pointed            D. announced

4. A. humour               B. direction                 C. responsibility   D. safety

5. A. Though               B. Since                   C. As               D. When

6. A. impression        B. colleague             C. fact               D. choice

7. A. in                     B. over                     C. about            D. through

8. A. greeting               B. present                 C. suggestion       D. ride

9. A. put up                 B. turned out               C. looked up         D. held out

10. A. when                 B. after                     C. until             D. since

11. A. nervous                    B. generous              C. distant          D. familiar

12. A. suggested       B. imagined              C. considered        D. appreciated

13. A. friendship       B. conversations     C. instructions      D. cooperation

14. A. and                    B. or                         C. but               D. so

15. A. earns                 B. devotes                   C. supports       D. sponsors

16. A. why                   B. how                     C. what             D. whether

17. A. praised            B. encouraged                     C. warned             D. thanked

18. A. must                 B. needed                        C. could            D. dared

19. A. pride                  B. fear                   C. trust            D. courage

20. A. turn against              B. leave out                 C. pick up          D. believe in