首页
登录
职称英语
The human heart is enclosed in a sac with a two-layered wall. A lubricating flui
The human heart is enclosed in a sac with a two-layered wall. A lubricating flui
游客
2024-01-02
52
管理
问题
The human heart is enclosed in a sac with a two-layered wall. A lubricating fluid fills the space between the two walls, enabling them to slide past each other as the heart pulsates. The heart is mostly cardiac muscle tissue divided into four chambers, two atria and two ventricles. The atria have relatively thin walls and function as collection chambers for blood. The ventricles have thicker walls and are much more powerful than the atria, especially the left ventricle, which must pump blood to all organs of the body. A When the heart beats, the ventricles contract and pump blood. As the heart relaxes after a contraction, the atria fill with blood. B One complete sequence of pumping and filling is called the cardiac cycle. C In an average adult at rest, the cycle takes about 0.8 second. The number of times the heart beats each minute is the heart rate, which can be measured by taking the pulse. D On average, a healthy adult at rest has a heart rate of about 70 beats per minute. An individual’s heart rate will vary, depending on the level of activity. [br] The word pulsates in the passage is closest in meaning to
选项
A、pumps
B、grows
C、weakens
D、divides
答案
A
解析
Pulsates means pumps in this context. Clues: ...slide past each other as the heart...; When the heart beats....
转载请注明原文地址:https://tihaiku.com/zcyy/3327989.html
相关试题推荐
Thehumanheartisenclosedinasacwithatwo-layeredwall.Alubricatingflui
Thehumanheartisenclosedinasacwithatwo-layeredwall.Alubricatingflui
Thehumanheartisenclosedinasacwithatwo-layeredwall.Alubricatingflui
Thehumanheartisenclosedinasacwithatwo-layeredwall.Alubricatingflui
随机试题
ManypaintingsoftheAmericanSouthwestconveyafeelingofisolationandlonel
NearlyhalfofUSemployersresearchtheonlineprofilesofjobcandidateso
26岁初孕妇,妊娠39周,不规律宫缩有3日,阴道少许血性黏液,查:血压135/9
从下泪点冲洗,水自上泪点射出,压力较大,鼻咽部无水。此为A.下泪小管阻塞 B.
根据《合同法》,下列关于定金的说法,正确的是()。A.债务人准备履行债务时,定金
患儿8岁,反复发作性短暂意识丧失,动作中止。智力基本正常为明确诊断应首选的辅助检
共用题干 某一房地产开发公司A公司拟获得某城市规划区内一地块建设商品住宅。某职
A.休克 B.水中毒 C.双侧肾盂输尿管梗阻 D.蛇咬伤 E.尿毒症可引
从所给的四个选项中,选择最合适的一个填入问号处,使之呈现一定的规律性:
如某公司以单利方式借入500万元,年利率10%,第4年末偿还,则第4年本利和是(
最新回复
(
0
)