"Millions do it". In this sentence "do it" refers to_____. Aeroplanes usually do not need to climb quickly or fly high in the p

admin2018-09-25  44

问题 "Millions do it". In this sentence "do it" refers to_____.
Aeroplanes usually do not need to climb quickly or fly high in the polar region because ______.

选项 A、they do not land there
B、there are no clouds at all
C、they can cross the ice with special equipment
D、it is very cold

答案B

解析 答案依据第二段最后两句:Nor can clouds."云在冷空气中上升得也慢";In practice,this is an advantage…keeps the clouds down low."实际上,这是对飞机的有利条件,当它到达北极上空的时候已经相当高了,不需要继续爬升,同时冷空气将云压低(这样不至于对飞机的飞行有不良影响)"。由这两句可知,在北极上空,空气较冷,冷空气将云向下压,云无法上升得很高,不会对飞机的飞行造成影响,故B项正确。
转载请注明原文地址:https://jikaoti.com/ti/9nDYFFFM
0

随机试题
最新回复(0)