A: Hi, Linda!
B: Hi, Michael!
A: bad weather! There is so much sand in the air.
B: So it is. when the sandstorm (沙尘暴) came?
A: I was waiting for the bus. There was lots of sand flying in the air when the wind was blowing strongly. So I couldn't see anything clearly outside.
B: But do you know what causes these sandstorms?
A: People do something bad, such as cutting down too many trees.
B: . I think we need to work hard to protect (保护) our environment.
A: I agree with you. We must protect our home —the earth.
B: make notices?
A: Good idea. Let's on weekends.
B: Then everyone will know how to protect our earth.
