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
外语
For several years, scientists have been testing a substance called interferon, a potential wonder drug that is proving to be eff
For several years, scientists have been testing a substance called interferon, a potential wonder drug that is proving to be eff
admin
2015-12-31
52
问题
For several years, scientists have been testing a substance called interferon, a potential wonder drug that is proving to be effective in treating a variety of ailments, including virus infections, bacteria infections, and tumors. To date, the new drug has provoked no negative reaction of sufficient significance to discourage its use. But in spite of its success, last year only one gram was produced in the entire world.
The reason for the scarcity lies in the structure of interferon. A species specific protein, the interferon produced from one animal species cannot be used in treating another animal species. In other words, to treat human beings, only interferon produced by human beings may be used. The drug is produced by infecting white blood cells with a virus. Fortunately, it is so potent that the amount given each patient per injection is very small.
Unlike antibiotics, interferon does not attack germs directly. Instead, it makes unaffected cells resistant to infection, and prevents the multiplication of viruses within cells.
As you might conclude, one of the most dramatic uses of interferon has been in the treatment of cancer. Dr. Hans Strander, research physician at Sweden’s famous Karohnska Institute, has treated more than one hundred cancer patients with the new drug. Among a group of selected patients who had undergone surgical procedures for advanced cancer, half were given conventional treatments and the other half were given interferon. The survival rate over a three-year period was 70 percent among those who were treated with interferon as compared with only 10 to 30 percent among those who had received the conventional treatments.
In the United States, a large-scale project supported by the American Cancer Society is now underway. If the experiment is successful, interferon could become one of the greatest medical discoveries of our time.
Interferon has not been widely used because it is________.
选项
A、still very dangerous
B、not yet available in the United States
C、difficult to produce in large quantities
D、not effective for human beings
答案
C
解析
文中第二段前三句说:“这种供不应求的原因在于干扰素的构成结构上。作为一种特殊种类的蛋白质,从一种动物身上产生出来的干扰素不能用在另一种动物身上。换句话说,用于治疗人体疾病的干扰素只能从人体内产生并提取。”由此我们可以推断出,在人体内生产干扰素是有难度的,因而大批量生产是困难的。因此选项C正确。本题通过排除法也可以确定答案。选项A说使用干扰素仍然非常危险,这不符合文中第一段内容,可排除;选项D说干扰素对人体无效,同样也与文中第一段内容不符,亦可排除;选项B说在美国仍没有使用干扰素,我们在文中最后一段得知,美国正在进行一项大规模的工程来生产干扰素,根据常识推断,干扰素一定在美国试用过,否则不可能进行大规模生产。由此选项B可以排除。
转载请注明原文地址:https://kaotiyun.com/show/7OWO777K
0
在职攻硕英语联考
相关试题推荐
A、Becauseshehadbecomeoverweight.B、Becausesheusedtotravelagreatdeal.C、Becauseshewastiredofherpreviousjob.D、B
Asamother,Iunderstandthepowerfulbondbetweenaparentandchild.Ilovemyson,andIreallywoulddoanythingforhim.S
A、GreenEggsandHam.B、ToKillAMockingbird.C、OfMiceandMen.D、AChildCalled"It".A“一年级小学生最喜欢读的是哪本书?”Thebookreadmosto
OneareainwhichLondonstillsurpassesitsrivalsisthenumberofinternationalvisitorsitreceives:morethananyotherin
______theirdifferences,theyareunitedbythecommondesiretotransformtheirpersonalcommitmentintopublicleadership.
Earthisbelievedto______byanobjectthesizeofMarsatsomepointinthedistantpastbeforeitssurfacecooled.
Aterminallyillpatientisonewho______.Thedifferencebetweenactiveandpassiveeuthanasiaiswhether______.
Woman:Ididn’tseeyouattheconcertlastnight.What’swrongwithyou?Man:That’snotmycupoftea.Question:Whatdoesthe
Wearesurethat______todothisfacetoface,hewouldfinditdifficulttoexpresshimselfwithoutlosinghistemper.
ReportersrushedtotheAirportaftertheCNNreportedthatninepassengers______bya"terrorist"ontheplane.
随机试题
小说的三要素包括______、______、______。
Yourideaseemstobegoodbutitisn’t______.
A.瞬时B.1~2周C.2~3周D.3~4周E.4~12周(2003年第105题)糖化血红蛋白A1反映取血前血糖水平的时间是
患儿,2岁,腹泻2天。3小时前突然剧烈腹痛、哭闹、呕吐、腹胀,20分钟前有少量果酱样粪便,右侧腹可触及香肠样肿物,长约6cm。患儿最可能出现了
A、义齿弹跳B、义齿摘戴困难C、恶心、唾液增多D、粘膜广泛压痛E、咬合时基牙酸痛、敏感卡臂尖过长、抵住邻牙
乙型肝炎病毒为DNA病毒,易变异,是致肝癌的重要因子,下列可以治疗乙型病毒性肝炎的药物有
食品安全,攸关百姓的生命健康,只有安全的食品才能使百姓“各安其居而乐其业,甘其食而美其服”。任何忽视食品安全的行为,就是挑战人类文明的______,漠视生命、践踏生命、甚至是______生命,早期的三鹿奶粉三聚氰胺食品安全事故就是最好的______。填入
隶书有秦隶和汉隶两种,属于古文字阶段的最后一种形体。()
版权、专利、商标等分别对应不同形式的发明创造。各自的待遇也不尽相同。专利、工业设计、集成电路设计、地理标示和商标需要先注册以便享受保护。注册要求对保护的内容进行描述,例如发明、涉及品牌名称、图标等。此类描述属于公共信息。版权、商业秘密在特定条件下享受自动保
Culturalglobalization,formany,meansWesternizationorAmericanization.Animportantdistinctionconcerningtoday’scultural
最新回复
(
0
)