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问题 单项选择题

切开与缝合肺组织的内镜切割缝合器（Endo-GIA）型号是：（）。

A.60～3.5mm

B.45～3.1mm

C.45～2.5mm

D.60～4.2mm

答案

参考答案：C

选择题

图中a、b、c、d四点为甲城市反气旋过境时的风向。读图回答题。

小题1:图中甲地：

A．位于南半球

B．位于北半球　

C．天气阴雨

D．昼夜温差小小题2:下面符合a、甲、b一线近地面等压面的弯曲状况的示意图为：

A                  B                  C                 D
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单项选择题

Why can human beings outlast many faster four legged animals when running long distances Perhaps because early humans evolved as hunters on the hot African savannas. Humans developed the ability to release heat by sweating, but most mammals must pant, a function hard to regulate while running. Also, four-legged animals must adopt a pace that lets them breathe once in mid-stride; otherwise, the impact of the front legs hitting the ground will prevent deep inhalation. Humans can vary the number of breaths per stride, set a pace unsuited to the prey, and so eventually exhaust it.
The author’s explanation of why human beings have evolved as superior distance runners would be most weakened if it were shown that

A．early humans typically hunted animals that were less well adapted than humans for long-distance running.

B．early humans were only one of a number of species that hunted prey on the African savannas.

C．early humans hunted mainly in groups by sneaking up on prey and trapping it within a circle.

D．hunting was just as essential for later humans in colder climates as it was for early humans on the African savannas.

E．(E) human beings of today have retained the ability to run long distances but no longer hunt by chasing prey.
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