單車

且足下昔以單車之使，適萬乘之虜，遭時不遇，至於伏劍不顧，流離辛苦，幾死朔北之野。

Thou too, O my friend, an envoy with a slender equipage, sent on that mission to the robber race, when fortune failed thee even to the last resource of the dagger. Then years of miserable captivity, all but ended by death among the wilds of the far north.

丈人視要處，窄狹容單車。

Please, sir, look at the vital place, so narrow that it allows but one chariot to go through.

踩單車

to bike; to ride a bike

共享單車

bike sharing