gravity low

例句：

1. 1. The weight of the earth onthe moon's surface is a mystery.
   月球表面地球的重量是一个谜。
2. 2. The gravityof the situation demanded immediate action.
   形势的严峻要求立即采取行动。
3. 3. The gravity of herwords was enough to make him feel ashamed.
   她的话的严肃性足以让他感到羞愧。