如果a是偶数，b是奇数，那么a+b一定是[ ]
A. 偶数
B. 奇数
C. 质数
D. 非零偶数
答案：B
The retired workers were invited to the company， ________surprise，changes had been so great over the years.
A．whose
B．who
C．to whom
D．to whose
一台IP地址为10.110.9.113/21主机在启动时发出的广播IP是（）
