完形填空。

Mrs White1in a school. It is Sunday. She has2classes. At eight in the morning, she3to a shop and buys a nice dress. She puts it in her bag and then buys4cakes for her children. At eleven，she5home. She wants to put on her new dress, but she6find her bag. She calls the shop assistant (售货员), "Hello, Mrs Black. This is Mrs White. Can you help7find my bag?8in your shop."

"Of course, Mrs White," says the assistant. "We found three bags here. But which one is9?"

"I'm10," says Mrs White, "I can tell you which one is mine."