载流导体三相短路时，电动力计算主要考虑工作条件最恶劣的一相，即（）。
A.A相
B.B相
C.C相
D.中间相
参考答案：D
Only when all the fish in the lake died _____ how serious the pollution was.[ ]
A. did the villagers realise
B. the villagers realised
C. had the villagers realised
D. the villagers had realised
对于数组，通常具有的基本操作有______种，它们分别是______。
