首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
专升本
Despite the fact that today viruses (病毒) are known to cause cancer in animals and in certain plants, there exists a great reluct
Despite the fact that today viruses (病毒) are known to cause cancer in animals and in certain plants, there exists a great reluct
admin
2011-07-31
49
问题
Despite the fact that today viruses (病毒) are known to cause cancer in animals and in certain plants, there exists a great reluctance to accept viruses as being of importance in human cancer. Basic biological phenomena generally do not differ strikingly as one goes from one species to another. It should be recognized that cancer is a biological problem and not a problem that is unique for man. Cancer originates when a normal cell suddenly becomes a cancer cell which multiplies widely and without apparent restraint. Cancer may originate in many different kinds of cell, but the cancer cell usually continues to carry certain traits (特性) of the cell of origin. The transformation of a normal cell into a cancer cell may have more than one kind of cause, but them is good reason to consider the relationships that exist between viruses and cancer.
Since there is no evidence that human cancer, as generally experienced, is infections, many persons believe that because viruses are infections agents they cannot possibly be of importance in human cancer. However, viruses can mutate (突变) and examples are known in which a virus that never kills its host can mutate to form a new strain of virus that always kills its host. It does not seem unreasonable to assume that an innocuous (无害的) latent (潜伏的) virus might mutate to form a strain that causes cancer. Certainly the experimental evidence now available is consistent with the idea that viruses as we know them today, could be the causative (引起……的) agents of most, if not all cancer, including cancer in man.
Cancer should be considered to be a biological problem rather than a medical one because ______.
选项
A、viruses are known to cause cancer in animals
B、at present, human cancer is not believed to be contagious (传染的)
C、there are many known causes for the transformation of a normal cell to a cancer cell
D、results of experiments on plants and animals do not vary greatly from species tn species
答案
D
解析
转载请注明原文地址:https://kaotiyun.com/show/0flC777K
本试题收录于:
英语题库成考专升本分类
0
英语
成考专升本
相关试题推荐
【B1】【B3】
ThecomputerDIDN’Thelpthepolice______.Thebesttitleforthispassageis______.
HowmanyoftheAmericansarelefthanders?Thereasonwhysofewareleft-handed______.
Theproblemrequiringimmediatesolutionwillbegiven______(prior)atthemeeting.
Thewitnesstoldthecourtthathe______theaccusedbefore.
Somepeopleare(fedupwithmoderncitylife)andhavemovedtothecountry.
Formally,intheUnitedStates,manynursesworkedasprivatedutynurses______inhospitals.
SeveralsmallearthquakeswerepredictedinNewYorkState,inthe______(east)partoftheU.S.A.
Tousitseemssonaturaltoputupanumbrellatokeepthewateroffwhenitrains,butactuallytheumbrellawasnotinvented
Mysisterhas______friendsatschool.Butshehas______goodfriends.
随机试题
二人爬楼梯,小王爬到第4层的时候,小李爬到第3层,问小王爬到第16层的时候,小李到几层?
我国监察机构在1958年前()
若3阶矩阵A的行列式|A|=-5,A*是A的伴随矩阵,则|A*|=_______.
在脊椎动物中,__________的光周期最为明显。
女性,30岁,因子宫肌瘤月经过多已经2年,Hb60g/L,RBC3×1012/L,MCV81fl。外周血象可见
患者,30岁,11月中旬发病,发烧、全身痛、尿少,入院时发病5天,查体可见面部充血,结膜出血,皮下可见瘀点、瘀斑,经化验检查,最后确诊为肾综合征出血热。哪一脏器的出血危险性最大()
为了有助于人们选择最满意的城市居住,有关部门实施了一项评选“最舒适城市”的活动。方法是,选择十个方面,包括社会治安、商业设施、清洁程度、绿化程度、教育设施、旅游文化景点等等,每个方面按实际质量的高低,评以1分至10分之间的某一分值,然后求得十个分值的平均数
资本主义劳动过程的特点包括()。
J.Martin指出,软件公司能成功的因素有Ⅰ.产品的易用性Ⅱ.产品的革新Ⅲ.产品的销售Ⅳ.提供用户资料的质量Ⅴ.国际市场和服务其中,哪些是关键因素?
第1小题:打开考生文件夹4下的Word文档WORD1.DOC,其内容如下:【WORD1.DOC文档开始】绍兴东湖东湖位于绍兴市东郊约3公里处,北靠104国道,西连城东新区,它以其秀美的湖光山色和奇兀实景而闻名,与杭州西湖、嘉兴南湖
最新回复
(
0
)