downward movement的用法和样例：
例句
- Characterized by or exhibiting an alternating upward and downward movement.
一上一下的上下的交互运动为特征的或表出现上下的交经运动的 - The lateral or downward movement of dissolved or suspended material within soil when rainfall exceeds evaporation.
淋溶作用当降雨量超过蒸发量时，土壤中溶解或悬浮物的向侧面或向下的运动 - A downward movement; descent.
向下的运动; 下降
