完形填空(共20小题；每小题1.5分，满分30分)
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。
The books in David’s schoolbag felt like bricks as he ran down the street.What he wanted to do was to play basketball with Eric.   21   his mother told him he would have to return his sister’s books to the library first.
He had   22   set foot in a library and he wasn’t about to do so today.He would just  23  
the books in the outside return box.But there was a   24  ;it was locked.
He went into the building,only a few minutes   25   closing time.He put the books into the return box.And after a brief   26   in the toilet,he would be on his way to the playground to   27   Eric.
David stepped out of the toilet and stopped in   28  —the library lights were off.The place was   29  .The doors had been shut.They   30   be opened from the inside.He was trapped(被困)—in a library!
He tried to   31   a telephone call,but was unable to   32  .What’s worse,the pay phones were on the outside of the building.  33    the sun began to set,he searched for a light and found it.
   34   he could see.David wrote on a piece of paper:“    35   !I’m TRAPPED inside!”and stuck it to the glass door.   36  ,someone passing by would see it.
He was surprised to discover that this place was not so unpleasant,   37  .Rows and rows of shelves held books,videos and music.He saw a book about Michael Jordan and took it off the shelf.He settled into a chair and started to   38  .
He knew he had to   39  ,but now,that didn’t seem to be such a   40   thing.
21.A.but                       B.because                     C.or                             D.since
22.A.ever                            B.nearly                       C.never                        D.often
23.A.pass                            B.drop                         C.carry                        D.take
24.A.problem               B.mistake                     C.case                          D.question
25.A.during                  B.after                         C.over                          D.before
26.A.rest                      B.break                        C.walk                         D.stop
27.A.visit                            B.meet                         C.catch                         D.greet
28.A.delight                 B.anger                        C.surprise                     D.eagerness
29.A.lonely                  B.empty                       C.noisy                        D.crowded
30.A.wouldn’t                     B.shouldn’t                   C.couldn’t                    D.needn’t
31.A.make                    B.fix                            C.use                           D.pick
32.A.get on                  B.get up                       C.get through                D.get in
33.A.If                         B.As                            C.Though                     D.Until
34.A.On time                                                   B.Now and then
C.By the way                                                  D.At last
35.A.Come                   B.Help                         C.Hello                        D.Sorry
36.A.Surely                  B.Thankfully                C.Truly                        D.Gradually
37.A.at most                 B.after all                            C.in short                            D.as usual
38.A.watch                   B.play                          C.read                          D.write
39.A.wait                            B.stand                         C.sleep                         D.work
40.A.bad                     B.cool                          C.strange                      D.nice