补全对话。(5%)
A:
last Sunday?
B: Yes, I did. My classmates and I went to plant trees.
A: How did you plant trees?
B: First, we
in the ground. Then, we
and put them into the holes.
After that, we
. We watered the young trees.
A:
?B: Yes, they are. They can stop the wind and they can make the air fresh and clean.
A: We should plant more trees.