And that's just pushing the accelerator pedal down on this bus.

这只是把这巴士油门踩下去。

Imagine you enter a car with no steering wheel, no brake or accelerator pedals.

设想一下，你进入了一没有方向盘、刹和油门。

No. If you step on the accelerator pedal you can flood the carburetor and your car will never start.

不要。踩油门话会向化器里灌油，这样你就再也启动不了了。

Or they can occur in proto-oncogenes, which normally code for proteins that promote the cell cycle - so they're the cell cycle's accelerator pedal.

基因突变也可以发生在原癌基因；原癌基因功能是编码促进细胞周期运转蛋白质，所以它算是细胞周期“油门”。