在网管上配置ZXMP-S200V1.0时，4＃槽位的光口应配置为几个（）.
A.1
B.2
C.3
D.4
参考答案：B
— Would you mind my coming over and having a look at your new garden? My little son's curious about
those roses you grow.
— _____. You're welcome. [ ]
A. Yes, I do
B. Not at all
C. Never mind
D. Yes, please
（）由加热中心、散热设备、供水管道、回水管道和膨胀水箱等组成。
A.自然循环热水采暖系统
B.机械循环热水采暖系统
C.低压蒸汽采暖系统
D.高压蒸汽采暖系统
