问题 填空题

嫁接中,接上去的芽或枝叫做______,被接的植物叫做砧木,嫁接时应使二者______紧密结合才能确保成活.

答案

嫁接是指把一个植物体的芽或枝,接在另一个植物体上,使结合在一起的两部分长成一个完整的植物体.嫁接时,接上去的芽或枝叫接穗,被接的植物叫砧木,嫁接时应当使接穗和砧木的形成层紧密结合,以确保成活,因为形成层具有很强的分裂能力,能不断分裂产生新细胞,使得接穗和砧木长在一起,易于成活.

故答案为:接穗;形成层

单项选择题
完形填空

第二节完型填空(共20小题;每小题1.5分,共30分)

阅读下面短文,掌握其大意,然后从36—55各题所给的四个选项(A、B、C和D)中,选出最佳选项

It was in late April, dangerously near the well – known AP exams, when the absurdity(无助的荒诞感) of my life struck me. I was making a   36   of problems to be discussed for the evening as usual. When I   37  the great number of things on the list—a literature essay, timelines for American History, a Spanish presentation and   38 for tests in both Calculus and Physics, I was overwhelmed(难以承受) to the point of   39   exhaustion (extreme tiredness). After -  school arrangements had already worn away my   40  . To keep myself awake at 11p.m. to finish five hours of   41  just seemed like too much to handle. I   42   at the computer screen with tears streaming down my cheeks,   43  my friend James about how stressed out I was over school.

His response was immediate. “Well,   44   did you decide to take five AP classes on the top of everything you’re doing?”

My response   45  just as quickly. “Because I need them for college. Harvard won’t   46   someone who doesn’t challenge themselves with difficult classes!”

The words sounded so   47   as I typed them on the screen that I   48  laughed out loud. I was supposed to be   49 myself not torturing(折磨) myself. That was the night I   50   that I didn’t need to deal with a course load of disastrous difficulty to   51   my own self – worth.

It was a little too late to   52   things, of course. The AP exams were about to go full – force,   53   were winding down, and most of my clubs and organizations were about to hold their end – of – year parties. Still, I   54 a valuable lesson. No college, one billion dollar endowment (资助) or not, is worth the   55   I went through last year. I wish I’d had someone to tell me sooner that I didn’t have to do everything. Colleges don’t really want overachieving robots, They want people with passion(love). It doesn’t matter whether you’re a policy debater or not, as long as you show that you’re going for the things you love.

36.A.list    B.box   C.film  D.car

37.A.listened to B.put up      C.looked at  D.found out

38.A.working   B.fighting    C.struggling D.studying

39.A.physical    B.nervous    C.constant    D.mental

40.A.patience    B.sense C.energy      D.evidence

41.A.sleep B.homework       C.essays       D.tests

42.A.knocked   B.pointed     C.stared       D.shouted

43.A.typing      B.messaging C.dealing     D.telling

44.A.who  B.what  C.how  D.why

45.A.received   B.made C.showed     D.came

46.A.want B.teach C.meet  D.respect

47.A.curious     B.ridiculous C.encouraging     D.disappointing

48.A.still   B.also   C.almost      D.even

49.A.admiring  B.inspiring   C.educating  D.challenging

50.A.realized    B.doubted    C.believed    D.guessed

51.A.know       B.prove       C.become     D.trust

52.A.keep  B.collect      C.change      D.forget

53.A.classes      B.exams       C.students    D.operations

54.A.had   B.learned     C.gave  D.took

55.A.plans B.lessons      C.hardship   D.Stress