There's four stroke motors, four stroke piston engines being the most common.

有四冲程电机，四冲程活塞发动机是最常见的。

The Chinese character WANG is composed of four strokes.

中国字“王”有4个笔划。

So let's talk about the four strokes of the motor.

所以让我们来谈谈四冲程电机。

So going back to the four strokes of the motor, the piston is forced down, as the piston is forced down, it's forced down on a crank shaft.

说回到四冲程电机，活塞被向下推，当活塞被向下推时，它被压在曲轴上。

Diesel requires heat and pressure, same concept, same four strokes, but the piston comes up, it's compressing the diesel and the air, but much higher pressure than a gasoline motor.

柴油需要热量和压力，相同的概念，相同的四冲程，但活塞上来，它会压缩柴油和空气，但压力比汽油发动机高得多。

He crept down the bank, watching with all his eyes, slipped into the water, swam three or four strokes and climbed into the skiff that did " yawl" duty at the boat's stern.

他爬下岸边，用眼睛注视着，溜进水里，游了三四下，爬上了在船尾做“摇摆”任务的小艇。