The falling leaves have deposited layer and layer, and the moss has tracked on the side sill of my old house.
落叶沉积了一层又一层，苔痕漫上了我旧日的门槛。

It is very important for you to remember them, so that you sill not make a fool of yourself when having a meal.
这很重要，免得你在就餐时闹出笑话。

a. The gap of car hall door sill on every floor should satisfy the value required in the civil engineering diagram.
轿厅门地槛的间隙各层需满足土建平面图规定值。

As restricted by conditions, large cross section factor and large moment of inertia are not adequate to be adopted on the main sill.
受条件限制主梁不适宜采用大截面系数和大惯性矩。