气缸 cylinder 是发动机的重要部件。大多数汽车内含有多个气缸，只有点着所有气缸，发动机才能顺利运行。我们可以用表达 to be firing on all cylinders 来形容工作进展得十分顺利或某人发挥出了其全部潜力，就如同开足了马力的汽车一样状态很好。它不光可以用来形容个人，还可以形容团队或群体状态绝佳的情形。
The team aren't firing on all cylinders but they still managed to win.
I've got a bit of cold so apologies if I'm not firing on all cylinders today.
That was a brilliant performance. The orchestra is certainly firing on all cylinders at the moment.
表达 in the firing line “站在火力线上”的意思是某人或事物成为事件或话题的众矢之的，即非常容易受人诟病，常被用来形容某人或某事物处于风口浪尖。
The athlete found himself in the firing line when he said that women should stay at home and not do sports.
Smoking has been in the firing line for many years.