首页
登录
职称英语
Scientists have established that influenza viruses taken from man can cause t
Scientists have established that influenza viruses taken from man can cause t
游客
2024-06-30
42
管理
问题
Scientists have established that influenza viruses taken from man can cause the disease in animals. In addition, man can catch the disease from animals. In fact, a great number of wild birds seem to carry the virus without showing an evidence of illness. Some scientists concluded that a large family of influenza viruses may have evolved in the bird kingdom, a group that has been on the earth 100 million years and is able to carry the virus without contracting the disease. There is even convincing evidence to show that virus strains are transmitted from place to place and from continent to continent by migrating birds.
It’s known that two influenza viruses can recombine when both are present in an animal at the same time, the result of such recombination is a great variety of strains containing different H and N spikes. This raises the possibility that a human influenza virus can recombine with an influenza virus from a low animal to produce an entirely new spike. Research is underway to determine if that is the way that major new strains come into being, another possibility is that two animal influenza strains may recombine in a pig, for example, to produce a new strain which is transmitted to man.
选项
A、cause ill health in wild birds
B、do not always cause symptoms in birds
C、are rarely present in wild birds
D、change when transferred from animals to man
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3657338.html
相关试题推荐
Scientiststhinkthedifferencebetweenanimalsandmenis______.[br]Now,sci
Manhasabigbrain.Hecanthink,learnandspeak.Scientistsusedtothink
Agrowinglistofestablishedcollegesanduniversitiesareextendingaccess
Agrowinglistofestablishedcollegesanduniversitiesareextendingaccess
Agrowinglistofestablishedcollegesanduniversitiesareextendingaccess
Whendidthescientistslearnagreatdealaboutsleepanddreams?In_________
Whendidthescientistslearnagreatdealaboutsleepanddreams?In_________
Whendidthescientistslearnagreatdealaboutsleepanddreams?In_________
Whendidthescientistslearnagreatdealaboutsleepanddreams?In_________
Withthepopulationexplosion,scientistswillhaveto______newmethodsofinc
随机试题
A.probablyB.plantC.reasoningD.abilityE.
TheStateBoardofRegentswillconsiderlettingalternativeteachertrainin
Teachingtodaydemandsmorethanjustcaringaboutchildrenandknowingone’
Peoplewhoare______towoolshouldn’twearwoolenclothing.A、sensitiveB、initiat
Ifthedrugproveseffectiveinhumantrials,itcouldenhancetheeffectiveness
[originaltext]Aquestionweoftenaskothersandarealsofrequentlyaskedbyo
痛风发作当尿酸排泄减少时,血尿酸浓度一般超过A、416mmol/L B、416
已知企业A的资产负债率为0.4,则其负债权益比为( )。A.2.5 B.1.
野外调绘成果经各级检查修改后方可移交下一个工序,移交前要进行成果整理,对于成果整
由于卖方原因未能达到技术性能考核指标时,为卖方进行考核的机会不超过()次。A.二
最新回复
(
0
)