对负载电流较大且经常变化的整流设备，一般都采用（）滤波方式。
参考答案：电感
7.1 wish I'd bought a few jars of honey. Did you notice the ones they____by the roadside?
A． were selling
B． are selling
C． have sold
D．had sold
植物细胞中具有色素的一组细胞器是（）。
A.线粒体和高尔基体
B.叶绿体和液泡
C.中心体和核糖体
D.内质网和液泡
