They mix with ice in the air and falltotheground as snow.
它们与空气中的冰混合，然后以雪的形式落在地上。
2
Galileo was not merely ambitious when he dropped objects of varying weights from the Leaning Tower at Pisa and timed their falltotheground.
伽利略从比萨斜塔上扔下不同重量的物体，并计算它们的下落时间。他要实现的不仅是他的勃勃雄心。
3
If it is displayed on such occasions, do not allow the flag tofalltotheground, but let it be carried high up in the air to form a feature of the ceremony.