选词填空（选词并用其适当形式填空）
purple    promise    hundred    taxi    monitor 
We choose Daming as our class ________. He always helps us.
Betty ________ never to lie(撒谎) to me from now on.
Beihai Park is a little far from here. Let’s go there by________.
This kind old man is not rich but he helps ________ of poor children.
It’s too cold today. His lips(嘴唇) change into________ .