The only problem was, nobody at the station had an arm small enough to actually reach in through the two-and-a-half inch opening and pack grease around the bearing.

可是执行这个办法的最后的一个困难在于站里没有一个人的手臂小到可以伸进这个只有2.5英寸的开孔，他们无法把油脂涂抹到轴承的四周。

youdao

The only problem was, nobody at the station had an arm small enough to actually reach in through the two-and-a-half inch opening and pack grease around the bearing.

可是执行这个办法的最后的一个困难在于站里没有一个人的手臂小到可以伸进这个只有2.5英寸的开孔，他们无法把油脂涂抹到轴承的四周。

youdao