Examples of this kind are dirt bikes that are designed to conquer hard, rough and grimy treks.

这方面的例子实物污垢自行车，目的是征服困难，粗糙和肮脏跋涉。

The Electra dirt bikes can reach speeds of up to 30 miles per hour and can hold up to 220 lbs.

污垢自行车的伊莱克特拉可以达到的速度高达每小时30英里，可容纳高达220磅。