冬季的海洋相对于大陆是冷的海洋，空气柱冷却收缩，气压升高
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气压日振幅随纬度的增高而减小。
A. 对
B. 错
污水排放标准可分为地方排放标准和一般排放标准两类。
A. 对
B. 错
Directions: You find your study load is too heavy. Write a letter to your college teacher to1) tell him/ her the need to drop two courses,2) explain the reasons, and3) ask if it is possible to obtain a refund
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