阅读短文，选择正确的一项。

      I'm Lucy. I love travelling (旅行). Every summer I go on trips. I often buy postcards and stamps there

and send the postcards to my friends. I usually send some e-mails to my friends, too. I tell them some

interesting stories. I want to invite (邀请) my friends to travel with me.

1. Does Lucy like to travel?

A. Yes, she does.

B. No, she doesn't.

2. What does she buy there?

A. A computer.

B. Some postcards and stamps.

3. She wants to tell her friends some stories. What does she do?

A. She writes a letter.

B. She sends some e-mails.

致癌物可分为（）、（）、（）三类。