使用钢筋调直机调直钢筋到末端时，操作人员应站立在设备4m以外，防止钢筋回弹伤人。
参考答案：错
Jim sold most of his things.He has hardly___left in the house.
A．anything
B．everything
C．nothing
D．something
指出A1、A3、Acm；AC1、AC3、Accm；Ar1、Ar3、Arcm各临界点的意义。
