阅读下面短文 , 从短文后各题所给的 A 、 B 、 C 和 D 四个选项中 , 选出可以填入空白处的最佳选项。 The snow was falling and the roads had become dangerous. The schools were dismissed early, but much to my surprise, my 1 wasn't canceled. So I went, feeling especially heroic. As far as I could see, I was risking my life to keep my 2 Snow or no snow, I would be on time for my scheduled donation at the local 3 center. When I got there, I discovered I wasn't 4 Four more “hero-types” were already lying back in donor chairs with lines 5 to their veins( 静脉 ), and machines quietly pumping away to 6 their life-saving gifts. Seeing my fellow donors honoring their own commitments, I realized why I was there. I lay back in my donor chair, ready to make a 7 to the life of someone I would never 8 To be honest, I'd never really thought about why I donate. I just did it 9 a few months ago, during one of my 10 donations I learned that my blood was specifically for a cancer patient and for a newborn baby—both patients needed what I would give in order to live. I've viewed my visits to the blood center 11 ever since. My wife Karen is a 12 too. And more importantly, she has been on the bone marrow( 骨髓 ) list for fifteen years, ever since she 13 to provide bone marrow to a kindergartner with leukemia( 白血病 ). That little girl died before Karen's bone marrow could help her, but Karen was called again recently. Her test results were still on file, and it turned out she was a potential 14 for someone else. The caller asked Karen if she would still be willing to become a bone marrow donor. “Yes,” she said and then immediately began answering questions on the pages of paperwork for further testing. It was to 15 against time. I wish I could say that this race was 16 Unluckily, it wasn't. The caller later thanked Karen for her participation and asked a few more questions—including whether or not she'd 17 on the donor list. “Of course,” Karen answered. Last week Karen gave blood and next week I'll make my usual donation. I'll clear an afternoon from my schedule and make an appointment. I don't know whose life my donation may 18 Most likely it will be a 19 but on any day the person needing blood could be you or me or maybe a loved one. It is worthwhile to 20 our time to donate. I really do feel proud every time I donate. And I like the feeling 1.A.appointment B.class C.training D.flight 2.A.secret B.balance C.shape D.word 3.A.service B.research C.blood D.care 4.A.alone B.welcome C.late D.lucky 5.A.exposed B.attached C.applied D.added 6.A.check B.produce C.collect D.clean 7.A.meaning B.decision C.difference D.choice 8.A.meet B.forget C.miss D.recognize 9.A.And B.But C.So D.Because 10.A.regular B.unexpected C.special D.pleasant 11.A.wisely B.differently C.hesitantly D.carefully 12.A.receiver B.doctor C.patient D.donor 13.A.built up B.signed up C.gave up D.took up 14.A.risk B.customer C.match D.partner 15.A.race B.struggle C.test D.write 16.A.fixed B.finished C.won D.shifted 17.A.rank B.sign C.appear D.remain 18.A.move B.affect C.create D.enrich 19.A.stranger B.child C.hero D.friend 20.A.waste B.save C.kill D.take