根据概念图，下列叙述正确的是
A．①表示的碱基有5种
B．②表示核糖
C．④表示核糖核苷酸
D．④表示脱氧核糖核苷酸
答案：D
The manager,________ it clear to us that he didn’t agree with us ,left the meeting room.
A．who has made
B．having made
C．made
D．making
委托代理协议怎么签？如何委托、变更诉讼代理人？
