下列各组物质不能发生反应的是[ ]
A、镁与稀硫酸
B、锌与硫酸铜溶液
C、铝与硝酸银溶液
D、汞与氯化铜溶液
答案：D
骨骼肌细胞膜上的受体是
A．β1B．β2受体C．M受体D．N1受体E．N2受体
The children were made ____ 12 hours a day.
A．work
B．worked
C．working
D．to work
