首页
登录
职称英语
Scientists have discovered that plants themselves produce many poisonous che
Scientists have discovered that plants themselves produce many poisonous che
游客
2024-06-16
59
管理
问题
Scientists have discovered that plants themselves produce many poisonous chemicals for (36)______ against insects. But insects have developed ways of (37)______ with them and, in fact, have been eating plants for about 250 million years. Now insects are using these same (38)______ to deal with man-made poisons—insecticides. This is why (39)______ of insects to insecticides has developed so (40)______.
What should be done? Scientists studying the problem suggest that farmers use less insecticides. At the moment, farmers (41)______ spray crops as a (42)______ against problems that are caused by large number of pests. They should, instead, spray only where pests have actually been seen. Secondly, farmers could use a (43)______ of two or three insecticides at once. (44)____________.
The most surprising suggestion, perhaps, is that at certain times of the year, (45)____________. The new insects will mate with those which survived from a certain kind of insecticide and will lessen the latter’s resistance to it.
(46)____________ , which may be resistant to all poisons invade our farms and devour our crops.
[br]
Scientists have discovered that plants themselves produce many poisonous chemicals for defense against insects. But insects have developed ways of dealing with them and, in fact, have been eating plants for about 250 million years. Now insects are using these same mechanisms to deal with man-made poisons—insecticides. This is why resistance of insects to insecticides has developed so rapidly
What should be done? Scientists studying the problem suggest that farmers useless insecticides. At the moment, farmers regularly spray crops as a precaution against problems that are caused by large numbers of pests. They should, instead, spray only where pests have actually been seen. Secondly, farmers could use a combination of two or three insecticides at once. To survive, the insects would need to become resistant to two or more insecticides at the same time.
The most surprising suggestion, perhaps, is that at certain times of the year, farmers should actually try to attract insects onto the crops they are trying to protect. The new insects will mate with those which survived from a certain kind of insecticide anti will lessen the latter’s resistance to it.
Scientist hope that these and other measures will postpone the day when farmers and scientists will have to stand by while new super-bugs which may be resistant to all poisons invade our farms and devour our crops.
选项
答案
to survive,the insects would need to become resistant to two or more insecticides at the same time.
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3636510.html
相关试题推荐
[originaltext]Ateamofscientistsrecentlybeganaprojecttomeasurethe
[originaltext]Ateamofscientistsrecentlybeganaprojecttomeasurethe
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
Scientistshavediscoveredthatplantsthemselvesproducemanypoisonousche
[originaltext]Onewaythatscientistslearnaboutmanisbyanimals,sucha
随机试题
(1)Withincreasingprosperity,WesternEuropeanyouthishavingaflingthat
Isthisfactory_____someforeignfriendsvisitedlastFriday?A、thatB、whereC、
胎盘完全形成在下列哪个时间A.妊娠1个月末 B.妊娠2个月末 C.妊娠3个月
企业人员管理,员工内部流动管理一般包括()。A.平级调动 B.岗位轮换 C
A.急性单纯性胆囊炎 B.急性结石性胆囊炎 C.胆总管结石感染 D.肝左叶
恶性贫血主要是由于缺乏<P>A.叶酸<br>B.钾盐<br>C.钙剂<br>D.
()的设备应满足有关技术条件。(A)就地操作(B)模拟操作(C)遥控操作
关于共同保险与再保险的区别,正确的是()。 A.前者有分散风险作用 B
2013年,某农户的劳动力既有从事第一产业劳动的也有从事非农产业劳动的,该农户第
患者,男性,30岁,渔民。3周来高热,疲乏不适,腹胀,食欲减退,应用抗生素后发热
最新回复
(
0
)