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
2023-09-24
9
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://www.tihaiku.com/zcyy/3041074.html
相关试题推荐
Itisreportedthatscientistshavedevelopedglassfibersasthinashumanhair
Accordingtotheobservationsofsomescientists,wewillbeshortofenergyin
Manyscientistsaresoconvincedofthebenefitsofchallengingthebrainthatt
Scientiststhinkthedifferencebetweenanimalsandmenis______.[br]Accordin
Whydon’tbirdsgetlostontheirlongmigratoryflight?Scientistshavepuzz
Scientistscandeterminesomeone’sfavoritefoodfromtheirbodyshape.They
Agrowinglistofestablishedcollegesanduniversitiesareextendingaccess
Scientiststhinklaser(be)______oneofthemostusefultoolstoday.tobe句意:科学
Whendidthescientistslearnagreatdealaboutsleepanddreams?In_________
Whendidthescientistslearnagreatdealaboutsleepanddreams?In_________
随机试题
促胃肠动力药适宜给药时间是()A:清晨 B:餐前 C:餐中 D:餐后
患者,男,72岁,体重55kg,因“反复咳嗽、咳痰5年,气短2年,加重1周”之主
视频传输通道主要指标问答(二)。(2)微分增益对图像质量的影响()。A.标
甲公司以一栋办公楼换入一台生产设备和一辆汽车,换出办公楼的账面原价为900万元,
(2020年真题)关于QDII基金的信息披露,以下表述错误的是()。A.当
A.正细胞正色素性贫血B.巨幼细胞性贫血C.小细胞正色素性贫血D.小细胞低色素性
行业分析方法中,历史资料研究法的不足之处是其()A:不能预测行业未来发展状况B
声誉风险是一种单一风险。()
我国从2004年起实施的《商业银行资本充足率管理办法》规定核心资本包括()。
共用题干 在房地产投资项目经济评价中,某房地产投资项目的总投资为10000万元
最新回复
(
0
)