问题 名词解释

细胞连接(celljunction)

答案

参考答案:

是指相邻细胞表面的某些局部区域存在的沟通细胞与细胞之间,细胞与细胞外基质之间的连接装置。动物细胞有三种类型的连接即紧密连接、锚定连接和缝隙连接。细胞连接不仅是细胞间机械联系、维持组织完整性的结构基础,同时,也是沟通细胞间物质交换与信息传递的重要途径,对于协调细胞间的代谢活动具有重要意义。

完形填空

第二节 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36~55各题所给的四个选项(A、B、C和D)中,选出最佳选项,并在答题卡上将该项涂黑。

When Alice started to cycle home from Jenny’s house, she wasn’t nervous. She was certainly not afraid of the dark.  36  , it was only a 15,ncnule ride home. But halfway there, she began to wish that he hadn’t been so   37  .

As she rounded a sarp benu, it suddenly   38   cold-very cold. Alice’s breath became puffs of white cloud and her legs aso cale that it became hard to ride.

With her liart beating fast, she struggled so hard to move   39   that the didn’t hear the car which suddenly appeared beside her. She stopped by the road. The big black car also   40  ,Slowly, the passenger-window began to slide down. Alice held her breath. In the soft light inside the car, something   41  . Then, the light brightened and Alice was staring at a sweet, grey-haired old lady. “Hello, dear,”said the old lady. “I need   42  . I’m afraid I’m lost. I need to find the nearest airport. I must be there in the next five minutes.”

“Airport? You   43   are lost,”Alice said. “You need to go back five kilometers   44   you reach the”

T-junction.Turn left and  45  for about another 10 kilometers to the main highway.From there,just follow the  46  to the airport.But I’m afraid there’s no  47  you’ll get there in five minutes!”

“Thank you very much,dearn eplied the old lady.“Don’t worry-I’ll  48  it time.”

The  49  up and the started off.A little way ahead,it  50  and with hedlights filashing, it drove past Alice. But then, mething  51  happened.The car hegary changing flrst, its color  52  from black to silvey grew when, the wheels began disappearing, but the car    to move forward,  53  just above the grolld. As the car  54  into the dark sky, the big red tail-lights grew larger and larger and glowed more and more brightly.With a faint whistling  55  ,the car was gone in seconds,leaving Alice shaking her head in disbelief…

36.A.However                     B.Besides              C.Therefore           D.Othrwise

37.A.brave                   B.excited               C.eurious               D.grew

38.A.fell                      B.around               C.forward              D.backward

40.A.arrived                 B.aopped               C.stayed                D.started

41.A.gathered               B.opped                C.stayed                D.started

42.A.help                            B.exicult               C.rest                    D.water

43.A.necess                  B.gas                    C.rest                    D.water

44.A.if                         B.until                  C.unless                D.as

45.A.drive                    B.walk                  C.follow                D.march

46.A.address                 B.sigms                 C.notiees               D.guidance

47.A.doubt                   B.room                 C.time                   D.way

48.A.have it                  B.get it                  C.make it                     D.finishit

49.A.door                     B.window              C.headlight            D.wheel

50.A.passed                  B.rashed                C.turned                D.continued

51.A.strange                 B.entive               C.imaginable         D.horrible

52.A.developen             B.apend                 C.spread                D.ladea

53.A.rollin                   B.floating              C.drawing             D.flashing

54.A.pointed                 B.returned             C.broke                 D.rose

55.A.tune                            B.voice                 C.sound                 D.tone

单项选择题