Larger particles get deposited in fans that point in the directionof surface winds, while smaller pieces remain suspended above.
大一些的微粒以扇状的形式沉积下来，扇尖朝向地面风的方向。 而小一点的微粒仍然在火星上空中漂浮。
2
That one would be pointing kind of to the back slightly up maybe, so like that. And now your middle finger is going to point in the directionof the normal vector.
曲面的方向有点向后向上,应该差不多像这样，那么现在你的中指,指的方向就是法向量的方向了。
3
Work is defined as the product of a force and the distance through which its pointof application moves in the direction of the force.