水泥电杆立起时，应将顶端封堵，防止电杆投入使用后，杆内积水浸蚀钢筋，导致电杆损伤。( )
参考答案：对
I guess Tom won’t keep on asking me the time from now on as he has had his watch .
A．being repaired
B．repairing
C．to repair
D．repaired
若等式（x﹣4）2=x2﹣8x+m2成立，则m的值是[ ]
A．16
B．4
C．﹣4
D．4或﹣4
