每季度对变电站电缆隧道和夹层，控制盘、配电盘和开关场区端子箱等的电缆孔洞防火封堵情况进行一次检查，发现问题及时处理。
参考答案：对
I''m surprised that he ____ to help me when I needed his help .
A．should refuse
B．would have refused
C．should have refused to
D．may have refused
控制症状、防止病情恶化和减少并发症属于（）
A.初级预防
B.次级预防
C.三级预防
D.病因预防
E.切断传播途径
