Jack usually chats _______ the phone _______ his friends.
A：with; on
B：on; at
C：at; on
D：on; with
下列都是现代生物技术应用的成果，其中所采用的生物技术不同的一项是（ ）
______sleep too late. It's bad for your health.
—Exactly! It can be dangerous.
