were tethered to the cell tower nearest the train.

经由离火车最近的信号塔转接
So one of those calls was made by our bomber.

其中就有设弹人打的电话
Do you remember a freight

你记不记得爆炸时
train passing by just before the explosion?

正好有辆货运列车经过
Yes.

记得
The explosion was timed to engulf the passing freight train

在爆炸发生的时刻货车刚好经过
which means,

这表明
the bomber had to be watching both trains when the call was made.

设弹人是在可见两车的情况下打的电话
52 callers, one of those is our bomber.

五十二个人其中一个是设弹人
I want you to concentrate on the passengers in your car.

我要你留意同车厢的乘客
Get to know them, narrow the suspect pool.

了解他们缩小嫌疑人范围
Look for ones who seem quiet or withdrawn,

留意那些不动声响或孤僻的家伙