首页
登录
职称英语
An adult giraffe’s head is about six feet above its heart. This means that to 【C
An adult giraffe’s head is about six feet above its heart. This means that to 【C
游客
2024-02-18
10
管理
问题
An adult giraffe’s head is about six feet above its heart. This means that to 【C1】______ enough blood up to the brain the circulatory 【C2】______ must be strong enough to keep the blood at very high pressure.
Biologists have known for some time that giraffes solve this problem by having 【C3】______ high blood pressure, about 【C4】______ that of human beings. But an international team of biologists began to 【C5】______ about this. If giraffes have such high blood pressure, they should have a 【C6】______ problem with swelling in their legs and feet. Why don’t giraffes have swollen feet?
Giraffes should have 【C7】______ problem, too. Every time they bend heads 【C8】______ to drink, the blood should 【C9】______ to their heads and have a hard time 【C10】______ back up (when the head is down) to the heart. How come giraffes don’t black out when they drink?
The answer to the 【C11】______ feet problem, the researchers found, is that giraffes have 【C12】______ the researchers call a "natural anti-gravity suit". It 【C13】______ out that the skin and other 【C14】______ in their legs and feet are 【C15】______ stiffer and tougher than those of other 【C16】______ . As a result, the blood vessels in the leg cannot swell.
Therefore, the blood has nowhere to go but back to the heart. What about blood rushing to the head 【C17】______ the giraffe bends down to drink? The researchers found that the giraffe’s jugular vein, which 【C18】______ blood from the head back to the heart, has lots of one-way valves in it. In the giraffe’s neck, there are lots of muscles that flex and relax repeatedly as the animal moves its head and sucks 【C19】______ drinking water. By squeezing the valved jugular vein, they 【C20】______ blood moving back to the heart even while the animal is drinking. [br] 【C20】
选项
A、permit
B、retain
C、prevent
D、keep
答案
D
解析
词义辨析题,空格所在句意为:通过挤压颈静脉的阀门,它们能______血液流回到心脏,甚至在长颈鹿喝水的时候也能,keep符合句意,所以D正确
转载请注明原文地址:https://tihaiku.com/zcyy/3461456.html
相关试题推荐
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
Anadultgiraffe’sheadisaboutsixfeetaboveitsheart.Thismeansthatto【C
随机试题
Amongthe15-year-oldchildren,some______bestudyinginuniversitywhileothe
消防水泵的供电,应在其配电线路的最末一级配电箱处设置自动切换装置。
根据2010年我国卫生工作的奋斗目标,到2010年国民健康的主要指标在经济欠发达
下列关于发、供电企业销售电力产品的增值税纳税义务发生时间的表述中,正确的有()
在运用分层法对工程项目质量进行统计分析时,通常可以按照()等分层方法获取质量原始
由于房屋的改建致使部分房屋拆除的,房屋共有权人应当申请房屋所有权( )。A:更
A.以疾病为中心 B.以病人为中心 C.以健康为中心 D.以保健为中心
(2018年真题)产妇小李产假前的月工资为6200元,其所在单位上年度职工月平均
合同复核人员审核合同的内容包括()。A.文本书写是否规范 B.内容是否与审批
男,40岁,渔民,居于血吸虫流行区,常有饮生水不良习惯,持续高热3周,弛张热40
最新回复
(
0
)