止推轴承轴向间隙一般为（）。
A、0.1～0.2mm
B、0.25-0.5mm
C、0.5～0.7mm
参考答案：B
— are you going to do?
—We are going to go for a picnic.
A. Where
B. What
C. Who
乳果糖治疗肝性脑病的作用机制是
A．吸附肠内毒素B．促进肝细胞再生C．抑制肠道细菌繁殖D．供给糖，以提供热量E．减少肠内氨的形成和吸收
