Arrows would continue to fly forward forever in a straight line were it not for gravity, which brings them down to earth.

要不是重力使箭掉落地上，它将会一直沿直线往前飞行。

《柯林斯英汉双解大词典》

It's a wave, not a straight line.

生活是不是直线，而是波浪线。

youdao

It traces an arc, not a straight line, as income increases.

当收入增高时，收入和身高关系呈弧形，而不是直线。

youdao

And they moved up the hill slowly, in a close group, not in a straight line.

VOA: special.2010.07.15

So, when the voltage difference between the plates is zero, or when we just don't have the plates there at all, the cathode rays are not bent, they just go right in a straight line, and they can be detected on this screen.

拐弯来测试它们是否带电,当两板之间电压为零，或者根本就,没有这两个板时，阴极射线是一条直线,它可以在屏幕上。

麻省理工公开课 - 化学原理课程节选

Now there many ways I can connect these two points together. The simplest way is to draw a straight line. It's called the linear interpolation. My line is not so straight, right here. You could do a different kind of line.

最简单的办法是,像这样画一条直线,这叫线性插值,不过我的这条线画得不太直，你也可以用别的办法,比如一条抛物线。

麻省理工公开课 - 热力学与动力学课程节选

Even if it's not a straight line from Siri to extinction, we humans should probably be watching our machines just a bit more closely.

CNN: Is AI a threat to humanity?

The horizon is a circumference, not a straight line, and the land below unrelentingly flat, divided only by orchards lined up like military regiments.

BBC: England's West Country: Still the apple of our eye

Italy hit back in similar fashion through Bergamasco - not regarded as a front-line Test goalkicker - straight after the restart when Nick Easter was penalised for not releasing after making a tackle, before a remarkable Wilkinson run came to an end.

BBC: Italy 12-17 England