Air is (1)_____, and like all matter, it has weight. Weight is the measure of the (2)_____ of gravity (3)_____ matter. If a scal

admin2014-06-13  25

问题     Air is (1)_____, and like all matter, it has weight. Weight is the measure of the (2)_____ of gravity (3)_____ matter. If a scale registers 10 kilograms when a stone is placed on it, this means that gravity pulls the stone with that (4)_____ force. (5)_____, earth’s gravity pulls on each (6)_____ of gas and dust on the atmosphere. Because our atmosphere is a. vast (7)_____ of air, it has (8)_____. If it could (9)_____ be compressed and put on a (10)_____ of scales, it would weigh about 5,700,000,000,000,000 (quadrillion) metric tons.
    The air pressed down on us and against us (11)_____ all sides. Something (12)_____ a ton of air is pressing against you at this moment. You are not (13)_____ of this because air pressure within your body (14)_____ the pressure of the air outside.
    Air pressure is 1.036 kilograms per square centimeter (14.7 pounds per square inch) at sea (15)_____. It is greatest there because that is the (16)_____ of the atmosphere. (17)_____ higher altitudes the pressure is (18)_____. That is why the (19)_____ of highflying planes are pressurized. They are designed to (20)_____ the air pressure our bodies must have.


选项 A、line
B、layer
C、bottom
D、point

答案C

解析 本题是一道词义辨析题。line的含义为"线";layer的含义为"层,面";bottom的含义为"底部";point的含义为"点"。根据上下文意,此处选bottom最合适。
转载请注明原文地址:https://jikaoti.com/ti/h7YRFFFM
0

最新回复(0)