问题 单项选择题

科学家发现,将一种从植物病毒中提取的基因注射到一种易受该病毒感染的植物的基因中可以提高该植物对这种病毒的抵抗力。由于病毒疾病引起的谷物损失占了很大的比重,这种基因转换,即便在一个最有限的范围内开展,也能显著减少谷物损失。下面哪个,如果正确,都将增强上述结论,除了:

A.在一些每年相继种植两种谷物的地区,如果保证第一种谷物不会感染一种病毒,另一种谷物通常也不会感染此病毒。
B.由于反复地侵入那些经过基因变异而成为抗体的植物,这些病毒对于那些没有发生基因变异的植物,不是那么致命了。
C.植物经历了基因变异,成为病毒的抗体以后,也会把这种抗体基因传给后代。
D.如果一种植物成为一种病毒的抗体,它会获得对相关病毒的抵抗力。
E.如果一种植物成为一种病毒的抗体,它会更容易受不相关的病毒感染。

答案

参考答案:E

解析:题干描述了一种做法,基因转换使植物对病毒的抵抗力提高。在选项中只要是这种做法的优点即为加强,缺点是削弱。E选项是缺点,其他选项都是优点。

完形填空
When Phillip was on his way to the airport one afternoon, he asked the driver to wait outside the bank while he collected some traveler’s checks.
The plane was to  21  at 5:30. From the bank there was still a 22  journey to the airport. Phillip merely (仅仅,只不过;只是)watched the  23   along the way. Shortly before arriving, he began  24 the things he would need for the 25 . Tickets, money, the address of his hotel, traveler’s checks—Just a moment. How about his passport? Phillip went through his pockets. He suddenly  26   that he must have left his passport (护照,通行证) 27 .
Whatever could he do? It was now five past four and there would be too little  28  to return to the bank. This was the  29   time he was representing(代表) his firm for an important  30  with the manager of a French firm in Paris the following morning. Without a passport he would be  31  to board the plane. At that moment, the taxi 32 outside the air . Phillip got out, took his suitcase and  33  the driver. He then  34  a good deal of confusion(混乱)in the building. A 35 could be heard over the loudspeaker.
“We very much 36 that owing to a twenty-four-hour strike (罢工)of airport staff(职员,员工), all flights for the rest of today have had to be called off.” Passengers are  37 to get in touch with their travel agents or with this terminal for 38 on tomorrow’s flights. Phillip gave a 39 . He would let his firm know about this situation and, thank goodness, he would have the opportunity of calling at his bank the following morning to 40 his passport.
小题1:
A.leaveB.registerC.check outD.pull
小题2:
A.pleasantB.shortC.longD.rough
小题3:
A.sceneryB.sceneC.viewD.sight
小题4:
A.countingB.looking overC.thinking aboutD.checking
小题5:
A.tripB.planeC.meetingD.flight
小题6:
A.remembered B.realizedC.noticedD.learned
小题7:
A.at homeB.at the officeC.at the bankD.in the taxi
小题8:
A.timeB.chanceC.possibilityD.use
小题9:
A.goldenB.lastC.onlyD.first
小题10:
A.journeyB.visitC.businessD.meeting
小题11:
A.sadB.unableC.impossibleD.difficult
小题12:
A.stoppedB.was drivenC.reachedD.was parked
小题13:
A.leftB.sent awayC.paidD.spent
小题14:
A.startedB.noticedC.caughtD.found
小题15:
A.speechB.noiseC.callD.voice
小题16:
A.apologizeB.announceC.worryD.regret
小题17:
A.advisedB.forcedC.toldD.persuaded
小题18:
A.ideasB.plansC.informationD.time
小题19:
A.loud laughB.deep sighC.big smileD.sharp cry
小题20:
A.returnB.findC.recoverD.gather
单项选择题