当工厂绝大部分负荷属于三级负荷且其少量一、二级负荷可由邻近低压电力网取得备用电源时,可装设多少台主变压器?()
A.1台
B.2台
C.3台
D.4台
参考答案:A
It's_____belief that parents have to spend nearly 500, 000 yuan bringing up a child in China
nowadays. [ ]
A. beyond
B. in
C. without
D. against
呼吸节律改变的病理意义是什么?