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
Scientists have learned more about the way cancer spreads from one place in the body to another. Once it spreads, it gets more d
Scientists have learned more about the way cancer spreads from one place in the body to another. Once it spreads, it gets more d
admin
2010-06-01
37
问题
Scientists have learned more about the way cancer spreads from one place in the body to another. Once it spreads, it gets more difficult to【B1】______.
Cancer is a disease of uncontrolled .cell growth. 【B2】______thinking is that cells simply break off the main cancer, travel through the blood and grow in other organs.
But the new【B3】______ suggest there is more to this process. Researchers found that cells from the main tumor send out messengers. These prepare the new organ for a【B4】______ tumor.
It works this way. The primary tumor releases proteins called growth factors into the blood. They【B5】______ cells at the target organ to produce a sticky protein, called fibronectin. Fibronectin attaches to the surface of bone marrow cells. The result is a kind of【B6】______ area for cancer to arrive and grow into a secondary tumor.
The bone marrow cells help make vessels for blood to pass through and【B7】______ the cancer cells. The researchers believe that without the bone marrow cells, the tumors could not land on the new【B8】______ and grow.
Scientists from Cornell University in Ithaca, New York, led the research. It involved laboratory mice.【B9】______. The mice were then injected with lung cancer cells. The researchers were surprised when the bone marrow cells reached the lungs days before any cancer cells. They found that the bone marrow cells arrived to prepare the lungs for the cancer to spread. Other tests led to similar findings.
【B10】______. They say knowledge of the process could lead to new ways to fight cancer.
Cancers can be caused by genetic or environmental conditions, or a combination.【B11】______. That includes better diet, exercise and no smoking.
【B4】
选项
答案
secondary.
解析
转载请注明原文地址:https://kaotiyun.com/show/ysN7777K
0
大学英语四级
相关试题推荐
Forthispart,youareallowed30minutestowriteacompositionentitledAreFamiliesDemandingTooMuchfromTheirChildren.Y
Adifficultorabusivebosscanpoisonthebestofjobs.Butyouarenotpowerless;beforeyouevenconsiderquitting,trytheb
Adifficultorabusivebosscanpoisonthebestofjobs.Butyouarenotpowerless;beforeyouevenconsiderquitting,trytheb
A、Writetheirlabreports.B、FindoutProfessorSmith’sschedule.C、Interviewsomehighschoolstudents.D、Finishtheirchemistr
A、Onabus.B、Onaplane.C、Onatrain.D、Inataxi.B根据选项,对话的内容与地点相关。对话中出现了“…goingtolandsosoon.”,说明他们是在飞机上,因此正确答案为B。
AFewyearsago,Iwasaskedtoanswerthisquestiononaradioprogram,"Whatisthebiggestlessonyouhaveeverlearned?"
Forcenturiesmandreamedofachievingverticalflight.In400A.D.Chinesechildren【S1】______withafan-liketoythatspunup
Whatcanweloamfromtheapproachtoscientificresearchinothercultures?ConsiderBritishscience.Inthe1980stomid-1990s
A、Theemployerandemployee.B、Theinterviewerandinterviewee.C、Theteacherandstudent.D、Thepoliceofficeranddriver.D该题
随机试题
数学老师准备上一节关于“概率”的代数课。课堂刚开始,数学老师提出一系列有趣的问题,比如:为什么我们花2元买彩票不一定中奖?如果我们花1亿购买彩票,然后让不同的人独自选号码,是不是保证一定中奖?在教学中,数学老师的这个教学阶段属于()。
内分泌腺的特征是腺细胞排列成________、________或呈________。腺细胞周围有丰富的________。分泌物称________,分泌后进入________周流全身。外分泌腺与内分泌腺比较,不同的是由________和________两部分
下列关于改革开放初期原有“四大专业银行”分工的说法中,不正确的是()。
已知:A公司拟于2009年1月1日购买某公司的债券作为长期投资,要求的必要收益率为12%。现有五家公司的债券可供选择,其中甲、乙、丙三家于2007年1月1日发行5年期,面值均为1000元的债券。甲公司债券的票面利率为10%,6月末和12月末支付利息
我国农历以干支纪年,1989年是农历己巳年,据此推算,20年后应该是()。
有了门,我们可以出去;有了窗,我们可以不必出去。窗子打通了人和大自然的_______,把风和太阳_______进来,使屋子里也关着一部分春天,让我们安坐了享受,无须再到外面去找。填入划横线部分最恰当的一项是:
在正偏态分布中,下列各数值最大的是
试述建构主义学习理论的基本观点,并说说其对实际教育有怎样的指导作用。
在采用点对点通信信道的通信子网中,如果两个节点之间没有直接连接的线路,那么它们之间的通信只能通过中间节点______。
SpeakerA:Goodmorning,sir.CanIhelpyou?SpeakerB:Yes,I’mleavingtoday.CanIhavemybillsettled?SpeakerA:Ofcours
最新回复
(
0
)