Factory equipment, automatic installation line group, spraying gravity line, co2 welding, presses, lathes, etc.

工厂设备齐全，自动安装线组，喷涂自流线，co2保护焊、冲床、车床等。

youdao

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》

The line the centre of gravity has to follow is indeed very simple, and in most cases, he believed, straight.

重心应当因循的线路确实非常简单，而且在大多数情况下，他相信，（只）是（简单）直线。

youdao

So engineers turned to steam engines to return the carts back up the line to the slate quarries before they were returned down the line under their own gravity.

BBC: The Princess in 1871

This exploits one of the predictions of Einstein's general theory of relativity: that the path of a beam of light (which is a straight line in empty space) is bent inwards by the gravity of a massive object.

ECONOMIST: Cosmology: I spy with my little gravitational lens | The

If an object floating through space passes near the line of sight between the earth and a distant star, its gravity should, according to the theory of relativity, bend and focus the light from that star.

ECONOMIST: The dark side of cosmology