虱的足,其胫节一部分与跗节和爪合抱,适于握持毛发,称为()。? ["A、捕捉足","B、开掘足","C、攀缘足","D、携粉足"]
发电机定子单相接地故障有何危害?
蝉属于()。? ["A、膜翅目","B、同翅目","C、鳞翅目","D、双翅目"]
下列哪种贫血属于典型小细胞低色素贫血() ["缺铁性贫血","再生障碍性贫血","溶血性贫血","巨细胞性贫血","海洋性贫血"]
口器嚼吸式,完全变态的昆虫是()。? ["A、沙蚕","B、蜜蜂","C、马蜂","D、家蝇"]
常用变压器有哪些种类?