derly need special care in winter, as they are______ to the sudden change of weather

Your mother prepared delicious food for us yesterday. Please say thanks ____ her.

Hi, Vera, have you checked the account yet?— Certainly, I ______ it five times even though you told me to do it twice.[ ]

I have heard of the famous scholar thousands of times but haven’r seen him _____ [ ]

He can play ______ volleyball, but he can’t play______ violin.