题目

细胞代谢中某种酶与其底物、产物的关系如图所示，下列有关叙述不正确的是（）       A．  酶1与产物B结合后失活，说明酶的功能由其空间结构决定       B．  酶1的变构位点和活性位点的结构取决于特定的氨基酸序列       C．  酶1有两种底物且能与产物B结合，因此酶1不具有专一性       D．  酶1与产物B的相互作用可以防止细胞生产过多的产物AWhen I was a teenager I volunteered to work at the water station at a 10,000 m race.      My  36 was to pass out water to the runners. I remember being so excited to see all the different kinds of    37  who passed by and   38 a cup of water. The next year I signed up for the   39  and gave it a shot.The first 10,000 m race was quite an experience. I jogged, I walked, I jogged and I walked. At times, I didn’t   40  if I could finish.At one point near the end, a 70-year-old man ran past me very   41  , and I felt embarrassed that I was 50 years younger than him and I couldn’t even keep up with him. I felt      42  for a second.But then I   43   something. He was running his race and I was running mine. He had   44  capacities, experience, training and goals for himself. I had mine. Remember my   45   was only to finish.After a minute, it   46 me that this was a lesson I could draw from . I learned  47 about myself in that moment. I turned my   48  into inspiration.I decided that I would not   49 running races. In fact, I would run even more races and I would learn how to train and  50 properly and one day I would be one of those 70-year-olds who were still running. As I   51 the finishing line, I was proud  52 my accomplishment.In life we all have those moments when we  53 ourselves to others. It’s only   54 . Don’ allow those moments to weaken you. Turn them into   55  and let them inspire you. Use them to show you what is possible.小题1:A．positionB．directionC．decisionD．target小题2:A．trainersB．runnersC．fansD．volunteers小题3:A．beggedB．drankC．droppedD．grabbed小题4:A．projectB．serviceC．raceD．experience小题5:A．doubtB．knowC．answerD．promise小题6:A．slowlyB．fastC．quietlyD．carefully小题7:A．surprisedB．satisfiedC．amusedD．defeated小题8:A．forgotB．realizedC．rememberedD．abandoned小题9:A．differentB．wonderfulC．valuableD．proper小题10:A．dreamB．planC．goalD．job小题11:A．happenedB．hitC．occurredD．attracted小题12:A．everythingB．anythingC．nothingD．something小题13:A．disappointmentB．embarrassmentC．agreement D．achievement小题14:A．sign upB．pick upC．give upD．keep up小题15:A．predictB．behaveC．prepareD．pretend小题16:A．foundB．crossedC．heldD．left小题17:A．inB．uponC．of D．for小题18:A．combineB．controlC．compareD．contribute小题19:A．naturalB．frequentC．importantD．terrible小题20:A．conditionB．motivationC．situationD．protection