已知点D、E分别在△ABC的边AB、AC上，下列给出的条件中，不能判定DE∥BC的是（　　）

A：Parks are really important in a neighborhood. ____

B：Sounds good.What can we do?

A：Well, we can pick up garbage(垃圾)．

B：What a great idea! ____

A：Yes, let's ask them to come.We can ask the neighbors, too.

B：____

A：We should bring garbage bags and buckets(水桶)．

B：____

A：Let's volunteer on Saturday.The weather will be sunny.

B：____ 

A：Wear old clothes.We'll probably get dirty.

B：OK.I will tell the others.

A．People must keep them clean.

B．When should we volunteer?

C．What should we wear?

D．Maybe we can invite our friends to help.

E．Let's volunteer to clean up Central Park.

F．I learned a lot from the activity.

G．What should we bring?