冷藏库平面布置最好成()。 ["长方形","三角形","正方形","圆形"]
正弦交流电的三要素是() ["最大值","相位差","初相角","角频率"]
在类Acoount中,正确引入类school.Student的语句是哪一项?() ["import school","import schllo.*","package school.Student","import Student"]
政治文化的特性是?
非均匀光纤中,纤芯中的折射率随半径的增加而按一定规律()。 ["先大后小","先小后大","减少","增大"]
森林的三大效益是什么?