右图是尿的形成示意图，据图分析并回答：（1）当血液流经肾_爱下问搜题

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问题实验题

右图是尿的形成示意图，据图分析并回答：

（1）当血液流经肾小球时，经过肾小球的作用，在肾小囊腔内形成液体A，液体A是。

液体A与血液相比，液体A中不含有。

（2）当液体A流经肾小管时，由于肾小管的作用，形成液体B，液体B是。

答案

（1）滤过原尿血细胞和大分子蛋白质。

（2）重吸收尿液

分析：本题考查尿的形成过程，即包括肾小球的和肾小囊壁的过滤和肾小管的重吸收．图中液体A是原尿，液体B是尿．

解答：解：当血液流经肾小球的和肾小囊壁时，除大分子的蛋白质和血细胞外，血浆中的一部分水、无机盐、葡萄糖和尿素等物质都可以经过肾小球过滤到肾小囊中形成原尿；当原尿流经肾小管时，原尿中的全部的葡萄糖、大部分的水和部分无机盐被肾小管重新吸收会血液，而剩下的水、尿素和无机盐等就形成了尿液．

（1）当血液流经肾小球时，经过肾小球的过滤作用，在肾小囊腔内形成液体A，液体A是原尿．由于肾小球不能过滤大分子的蛋白质和血细胞，因此液体A原尿与血液相比，液体A中不含有大分子的蛋白质和血细胞．

（2）当液体A流经肾小管时，由于肾小管的重吸收作用，形成液体B，液体B是尿液．

故答案为：（1）滤过；原尿；大分子的蛋白质和血细胞；（2）重吸收；尿液．

点评：关键知道尿的形成过程，即包括肾小球的和肾小囊壁的过滤和肾小管的重吸收．是中考的重要考点，应理解掌握．

判断题

当流体流动时，在流体层间产生阻力的特性称为流体的粘滞性。

填空题

(41)Orientation
Yellowstone is much more than hot ground and gushing steam. Located astride the Continental Divide, most of the park occupies a high plateau surrounded by mountains and drained by several rivers. Park boundaries enclose craggy peaks, alpine lakes, deep canyons, and vast forests. In 1872, Yellowstone became the world’s first national park, the result of great foresight on the part of many people about our eventual need for the solace and beauty of wild places.
(42) When to Go
More than half of the 3 million annum visitors come in July and August. In September and early October, the weather is good, the visitors few, and the wildlife abundant. In May and June, you can see newborn animals, but the weather may be cold, wet, and even snowy. Between about No-vember 1 and May 1 most park roads are closed to vehicles.
(43) Getting There
(44) How to Visit
The 142-mile (228.5-kilometer) Grand Loop Road forms a figure eight, with connecting spurs to the five entrances. On any visit, start with the geyser basins and Mammoth Hot Springs to see wildlife and thermal features (caution: both can be hazardous if approached too closely). On the second day, travel to the Grand Canyon of the Yellowstone, Hayden Valley, and Yellowstone Lake.
(45) Park Information
Park opens year-round.
[A] Road from North Entrance to Northeast Entrance open all year; most other park roads closed to cars November through April. Call headquarters for latest weather and road conditions.
[B] Facilities for Disabled Visitor centers, Madison and Fishing Bridge Campgrounds, most rest rooms, amphitheaters, numerous ranger-led activities, walks, and exhibits are wheelchair accessible. Free brochure available.
[C] On a longer stay, visit the Northern Range, or consider a boating or fishing trip on Yellowstone Lake; a backcountry excursion on foot or horse; or any of the numerous easy nature trails throughout the park.
[D] In early years, what made Yellowstone stand out was the extravaganza of geysers and hot springs. The wild landscape and the bison, elk, and bears were nice but, after all, America was still a pioneer country filled with scenic beauty and animals.
[E] By Plane
West Yellowstone Airport (WYS) at the West Entrance of Yellowstone. (This airport is open June through September.)
Cody Airport (COD) about 50 miles (81 kilometers) from the park.
[F] During the winter season, mid-December to mid-March, Yellowstone becomes a fantasy of steam and ice; facilities are limited but sufficient. Only the road between the North and Northeast Entrances stays open to cars, but snowmobiling is permitted on unplowed roads. Heated snow coaches offer tours and give cross-country skiers access to the 50 miles (80.5 kilometers ) of groomed trails.