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
A、They defend the bone against viruses. B、They prevent oxygen from entering the bone. C、They break down bone tissue. D、They conn
A、They defend the bone against viruses. B、They prevent oxygen from entering the bone. C、They break down bone tissue. D、They conn
admin
2004-12-29
72
问题
W: ok, last night you were supposed to read an article about human bones. Are there any comments about it?
M: well, to begin with, I was surprised to find out there were so much going on in bones. I always assumed they were pretty lifeless.
W: Well, that’s an assumption many people make. But the fact is bones are made of dynamic living tissue that requires continuous maintenance and repair.
M: Right. That’s one of the things I found so fascinating about the article the way the bones repair themselves.
W: Ok. So can you tell us how the bones repair themselves.
M: Sure. See, there are two groups of different types of specialized cells in the bone that work together to do it. The first group goes to an area of the bone that needs repair. This group of cells produce the chemical that actually breaks down the bone tissue, and leaves a hole in it. After that the second group of specialized cells comes and produce the new tissue that fills in the hole that was made by the first group.
W: Very good. This is a very complex process. In fact, the scientists who study human bones don’t completely understand it yet. They are still trying to find out how it all actually works. Specifically, because sometimes after the first group of cells leaves a hole in the bone tissue, for some reason, the second group doesn’t completely fill in the hole. And this can cause real problems. It can actually lead to a disease in which the bone becomes weak and is easily broken.
M: ok, I get it. So if the scientists can figure out what makes the specialized cells work, maybe they can find a way to make sure the second group of cells completely fills the hole in the bone tissue every time. That’ll prevent the disease from every occurring.
选项
A、They defend the bone against viruses.
B、They prevent oxygen from entering the bone.
C、They break down bone tissue.
D、They connect the bone to muscle tissue.
答案
C
解析
What is the function of the first group of specialized cells discussed in the talk?
转载请注明原文地址:https://kaotiyun.com/show/2O8O777K
0
托福(TOEFL)
相关试题推荐
Choosethecorrectletter,A,B,CorD.Writeyouranswerinbox40onyouranswersheet.Whichofthefollowingstatementsbes
AnswerthequestionsbelowusingNOMORETHANTHREEWORDSfromthepassageforeachanswer.Writeyouranswersinboxes22-26on
Lookatthefollowingstatements(Questions34-40)andthelistofcountriesbelow.Matcheachstatementwiththecorrectcountry.
AnswerthequestionsbelowusingNOMORETHANTHREEWORDSfromthepassageforeachanswer.Writeyouranswersinboxes31-33on
LookatthefiverestaurantadvertisementsA-Ebelow.Forwhichrestaurantarethefollowingstatementstrue?Writethecorrec
Airtransportwillbesafebecauseof
ReadingPassage1hasnineparagraphslabelledA-I.Whichparagraphcontainsthefollowinginformation?Writethecorrectletter
Lookatthefollowingresearchers(Questions19-22)andthelistoffindingsbelow.Matcheachresearcherwiththecorrectfinding
Thievesoftentargetstudents’homesbecausestudents______.The______isvaliduntiltheendofJune.
Completethetablebelow.WritetheappropriatelettersA-GagainstQuestions36~40.MAINROLES(A
随机试题
患者,女,27岁。近半个月来,夜间难以入睡,寐而易醒,故来就诊。刻下症见:精神疲惫,头晕耳鸣,腰膝酸软,五心烦热,遗精盗汗,舌红,脉细数。对于较重的不寐患者,四神聪可
对放射线中度敏感的肿瘤是
某进口设备,离岸价为200万元,到岸价为210万元,银行手续费为1万元,进口关税为21万元,增值税税率为17%,不计消费税,则增值税税额为()万元。
根据规定,增值税纳税人以一个季度为纳税期的,自期满之日起法定期间内应办理申报纳税,该期间为()。
工作结果型的绩效考评指标包括()
警察是具有()性质的维护社会秩序、保卫国家安全的国家行政力量。
塑料袋消费者中的一些人不是因为缺乏环保意识,而是贪图个人方便。在他们眼中,“塑料袋”等同于“方便袋”——现买东西即送袋子,省事省力又免去了上班拎布兜、菜篮的尴尬。殊不知,环境保护是利人利己、造福子孙的大事,每人每天使用一两个塑料袋,享受一两次方便,十几亿人
寸:尺
若视频图像每帧的数据量为6.4MB,帧速率为30r帧/秒,则显示10秒的视频信息,其原始数据量是()。
Iftherequiredreserveratiois10%andabankhas$50000incheckabledeposits,then
最新回复
(
0
)