These people are wearing masks beca

These people are wearing masks because of the smog. One cause of smog is automobile exhaust.It's raining hard, so you need an umbrella. Heavy rain like this can cause flooding and mudslides. When the sky is overcast, we can't see the sun because of the clouds. A cloudy sky means that it might rain. We need to wear a coat when it is cold and windy. In a very strong wind, it's difficult to use an umbrella. We need to drink water or other liquids when it's hot outside. When it's really hot, most people turn on the air conditioning.What kind of sky means that it might rain?