将表示实体特征的文字、数字或记号直接作为编码的是______
A．顺序码 B．成组码C．重复码 D．表意码
参考答案：D
Mr. Black ________ for Shanghai in a few days. Do you know when the earliest plane ________ on Sunday?
A．leaves; takes off
B．leaves; is taking off
C．is leaving; is taking off
D．is leaving; takes off
违约责任承担方式有哪些
