WD-320动力稳定车的液压系统按职能可分为（）个液压回路。
A、3
B、4
C、5
D、6
参考答案：B
After school we went to the reading-room to do some reading, only to be told that it .
A．is decorated
B．was decorated
C．was being decorated
D．is being decorated
计算题：根据下列水质的分析结果计算；（1）阴阳离子含量是否确：（2）各类硬度值。 Ca2+：54mg/L；HCO：170.8mg/L；Mg2+：9.6mg/L；SO：43.2mg/L：Na+：11.5mg/L：CL-：10.65mg/L；
