题目

一排有9个座位，4个人坐在上面，要求每两人之间至少有一个空位，则一共有多少种不同坐法？ 答案：解析：假设4人已经坐好，因为这4人每两人之间至少有一空座位，即意味着这4人被一些空座位隔开（或说插空坐）.因此可以换一种说法：把4人插入5把椅子之间的空隙中，方法为=360种，故不同的坐法有360种. 完形填空.      Yesterday, our teacher asked us when people could be considered old. David said thatwhen people got wrinkles (皱纹). However, Mary didn't__1__. She thought people might gain wrinkles at an earlier age because of their__2__work. Then Lily said that those__3__their 60s or more could be called old people. This time, Emily expressed her doubt. She said that some old people might__4__be full of energy and working on their dreams, which made them appear__5__ .The class was over and the teacher asked me to continue to__6__it after class.     The question__7__me of a saying of J.Barrymore: a man isn't old__8__ he is pursuing (追求 ) something.     My grandma is such a woman who__9__her dream even when she's 70 now. She has kept her dream of being a painter since she was a little child__10__, because her family waspoor, she had to__11__ her dream. She had to work to raise money so as to__12__ her family. Although she had never forgotten her dream, she could hardly find any__13__to makeit come true because of the tough work. Fortunately, a(n)__14__ came when she retired fromher work. She__15__taking painting lessons even though she was already old. At first, I was__16__ her idea of attending school at such an old age, but after seeing her paint happily andenjoyably, I began feeling it a good__17__.She looks fine and seems__18__.     So if we have our dreams and try to__19__ them, we aren't old. If we don't know what we want and let regrets be the__20__point of our lives, then we can be considered old. (     )1.A.answer(     )2.A.exciting(     )3.A.reaching(     )4.A.sometimes(     )5.A.attractive(     )6.A.think about(     )7.A.prevented(     )8.A.even if(     )9.A.remembers(     )10.A.However(     )11.A.give up(     )12.A.combine(     )13.A.way(     )14.A.success(     )15.A.stopped(     )16.A.on(     )17.A.choice(     )18.A.gentle(     )19.A.satisfy(     )20.A.tip B.agree B.common B.avoidingB.almost B.young B.look for B.spotted B .as ifB.followsB.Also B.search forB.protect B.person B.chance B.considered B.for B.dream B.energetic B.express B.bottom C.move C.hard C.repeating C.hardly C.smart Crefer to C.reminded C.so that C.knows C.FortunatelyC.put aside C.leave C.place C.excuse C.liked C.against C.tas k C.wealthy C.change C.center D.understand D.oldD.confirming D.stillD.interesting D.turn toD.puzzledD.as long as D.findsD.ApproximatelyD.return toD.supportD.serviceD.helper D.beganD.with D.purposeD.pennilessD.realizeD.side