a wet sidewalk的用法和样例：
- Everybody that was not invited was as mad as a wet hen.
- Sponge down the surface with a wet cloth.
- In wintertime he will don a wet suit and go right on surfing.
- He damped the table down, and then rub it with a wet cloth.
- Don't bring Robert to the picnic. He's such a wet blanket.
- Smother the flames from the burning pan with a wet towel.