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

这只是把这巴士的油门踩下去。

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

设想下，你进入有方向盘、刹车和油门的汽车。

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

不要。踩油门的话会向汽化器里灌油，这样你的汽车就再也启动不。

4.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；原癌基因的功能是编码促进细胞周期运转的蛋白质，所以它算是细胞周期的“油门”。