(x+1)(2x+1)10=a0+a1(x+2)+a2(x+2)2+…+a11(x+2)11,则a0+a1+a2+…+a11的值为
A.0
B.-1
C.1
D.2
答案:A
There used to be a tall tree in front of our classroom, ____? [ ]
A. used there
B. didn't there
C. wasn't there
下列哪项最好的支持通讯可用性()。
A.动态实时告警系统做网络监控
B.集成的纠正性网络控制
C.冗余
D.高速网络吞吐率