第12题: [单项选择]A block and tackle is “rove to advantage”. This means that the(). A. blocks have been overhauled B. hauling parts of two tackles are attached C. hauling part leads through the movable block D. hauling part leads through the standing block 参考答案:C
第13题: [单项选择]电压器油枕的作用()。 A. 防止油箱爆裂 B. 绝缘散热 C. 发出报警信号 D. 隔绝空气,避免潮气侵入 参考答案:D