at strain的用法和樣例：
例句
- He is working hard at this thesis.
他正在努力地撰寫論文。 - I study my English lesson very hard at school.
在學校我很努力地學習我的英語課。
辭彙搭配
- strain at a gnat 謹小慎微
- strain at 用力
- strain at the leash 牽扯皮帶
- strain at something 使勁拉某物
- strain at a gnat and swallow a camel 拘於小事大事糊塗...
