配送的最后一个环节是( )。
A．签收作业B．收退作业C．核单作业D．返品处理
参考答案：C
Last week only two people came to look at the house, _____ wanted to buy it. [ ]
A. none of them
B. both of them
C. none of whom
D. neither of whom
缘龈炎的临床表现是
A．疼痛明显B．自发出血C．牙周袋形成D．牙排列拥挤E．牙颈部常有牙石、软垢沉积
