An electric motor helps the operator pull a heavy load or go up a hill.

VOA: special.2009.05.11

If you go to the very top of Kearny, there's Coit Tower up on the hill there. That's really cool.

如果你走到干尼街的尽头，就会看到山顶上的科伊特塔。那里很棒。

旧金山的热点 - SpeakingMax英语口语达人