单项选择题 With No~1 and No~2 alternators running in parallel and the KW loads equally shared, one alternator is drawing much higher current than the other.What does this indicate?（）

单项选择题 Operational amplifiers, used primarily in analog circuits, are characterized by（）

单项选择题 CFC refrigerants exposed to high temperature or direct flame, will decompose and may produce（）