题目内容：

The young engineer sat down on a rock and rested his head in his hands. He would never get home; it was   36   . For weeks he had been   37  in the Northwest Canadian forest. Now there was a terrible   38   behind his eyes, and   39   of all, he had gone blind.

Suddenly a man  40  out of the woods, an Indian who had been hunting in the area. Seeing the engineer's  41   , he caught a fish in a nearby   42   and fed the sick man the  43   of the fish and some flesh from its head.  44   within a few hours the engineer's pain was   45   . A day later he could  46  again, and the next day he had  47  recovered.

When he returned home, the engineer told the  48   to Dr Price.   49   years later did it become a(n)   50  fact that this was just an everyday lifeguard doing its work. For what the engineer did, by eating fish eyes, was to   51  vitamin (ά����).

Vitamin A's biggest job is to keep the eyes   52  . Without Vitamin A, people and animals get night blindness and other eye problems. Without Vitamin A, people can even be totally blind. Vitamin A helps to keep the skin in good   53  . A also helps  54  bones and teeth and has something to do with proper   55   of blood cells.

1.A. hopeless                        B. useless                  C. careless               D. timeless

2.A. lost                                 B. losing                     C. hunting                D. working

3.A. disaster                          B. illness                    C. pain             D. heat

4.A. good                               B. bad               C. best             D. worst

5.A. reached                         B. appeared     C. hid                        D. watched

6.A. starvation                      B. trouble                  C. reality                   D. situation

7.A. pond                              B. stream                   C. place                    D. sea

8.A. tail                                  B. skin               C. eyes                      D. bone

9.A. Possibly                 B. Immediately          C. Fortunately          D. Surprisingly

10.A. gone                        B. shown                  C. settled                  D. disappeared

11.A. speak                       B. see                        C. walk                      D. work

12.A. completely              B. naturally               C. partly                     D. physically

13.A. news                        B. result                    C. secret                   D. story

14.A. Unless                               B. After                     C. Not until     D. When

15.A. recognized              B. accepted              C. solved                   D. explained

16.A. keep                        B. bring                     C. take             D. try

17.A. working                       B. rolling                    C. moving                 D. going

18.A. place                        B. order                    C. shape                   D. sense

19.A. from                         B. by                          C. about                    D. with

20.A. type                         B. growth                 C. choice                  D. size