at the back of: 在…后面
More importantly, she never again stood at the back of the line.
更為重要的是，她再也不躲在隊列的末尾了。
We may detect at the back of it a characteristically british reluctance to regard any one system as the best of all.
我們可以發現在其背后，英國人典型地不愿將之視為最好的一種制度。

pass by sb: 從某人身邊經過
Write this promise out on a piece of paper and post it somewhere that you pass by every day.
將這一承諾寫在一張紙上，將它貼在你每天要經過的地方。
People that pass by the area will see your name on the sign announcing your sponsorship.
路過的人們會看到宣布你認領的標志上你的名字。

at one’s mercy: 在某人的控制下
We cannot afford a future in which knowledge is at the mercy of popularity and money.
在知識受流行度和金錢支配的未來，我們無法承受之重。
We are otherwise at the mercy of the geopolitical weather.
否則，我們只能聽憑地緣政治氣候的擺布。