37. last month / we / plant / trees / park.
-> Last month, we planted trees in the park.
38. then / we / water / them / two or three weeks.
-> Then, we watered them for two or three weeks.
39. now / trees / grow / very well.
-> Now, the trees are growing very well.
40. they / make / park / greener / air / fresher.
-> They are making the park greener, and the air fresher

37. last month we planted trees in the park.
 

1. last month, we planted tree in the park\
2. then we, watered them for or two or three weeks
3. now, the tree are growing very well
4. they are making the park greener, and the their fresher