引起慢性肾衰竭最常见的继发性肾脏疾病是（）
A.慢性肾小球肾炎
B.糖尿病肾病
C.高血压肾病
D.狼疮性肾炎
E.梗阻性肾病
参考答案：B
— He is working hard now.
— He tries ___ English. So he practices ___ English every day.
A．to learn, to speak
B．learning, speak
C．to learn, speaking
D．learning, to speak
主机高压转子由哪些轴承支承？
