单项选择题
Electric insulation is made of organic substances and so gradually （） with age.
A.deteriorates B.increases C.are fouled D.becomes better
单项选择题 On commonly used ships,if two A√Cgenerators are operated in parallel, the load is distributed evenly by （）.
单项选择题 Moisture in a D-Cmotor would cause （）.
单项选择题 Prior to any overhaul work on electric equipment, it is important to ensure the circuits are （）.
