采用累积生息的红利领取方式的，红利累积利率的有效期至少为（）。
A.3个月
B.6个月
C.9个月
D.12个月
参考答案：B
What do you _____ the transportation in your city? [ ]
A. think over
B. think about
C. think of
D. think to
选择PLC机型时应考虑哪些内容?
