听力原文：

G: What were you doing when your teacher walked into the classroom just now, Luke?

B1: I was checking my e-mails at that time.

G: Hunter, what about you?

B2: I was chatting with a friend online.

G: What was Ben doing then?

B2: He was sleeping when the teacher came in.

G: What was Grace doing?

B1: She was listening to music while her deskmate, Kayla, was doing her homework.

Question: Who was doing homework when the teacher walked into the classroom?

参考答案：

Kayla was doing her homework.