高空探测的任务是探测地面至高空（）以下大气中（）随高度的垂直分布规律。
A. 20Km；温度、气压、湿度和风
B. 30Km；温度、气压、湿度
C. 30Km；温度、气压、湿度和风
系留气球探测特别适用于（）。
A. 大气污染监测和研究大气边界层等
B. 研究电离层、太阳紫外辐射等
C. 测量气团属性变化和大气电学特性
D. 探测台风、强风暴等
- Do you know _____ ?- Let me see. I remember it was on March 18th.
A. why did they move here
B. why they moved here
C. when did they move here
D. when they moved here
- I'd like to know _____ for the party.- I have no idea.
A. why did she buy so little food
B. what she has prepared
C. whether will she dance
D. when is she leaving
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