word of mouth例句

The story has been passed down by word of mouth.
这个故事是口头流传下来的。

I have informed him by word of mouth.
我已口头通知他了.

My products aren't based on advertising hype, they sell by word of mouth.
我的产品销售靠的不是天花乱坠的广告宣传，而是良好的口碑。