水电站中压缩空气有哪些作用？
核酸可分为核糖核酸（RNA）和（）（DNA）两大类。
假怒反应
卷边接头一般用于（）。 ["0.1～2mm的薄板","2～3mm的薄板","大于3mm的板","大于6mm的板"]
Which three functions can an Integrated Services Router perform in a VoIP network？（） [" voice stream mixing for conference calling"," voice gateway"," call admission control"," analog or digital phone interfaces"," XML application services"," large scale dial plan applicatio"]
古代汉语宾语前置可以分为分为三个类型：一是（）；二是（）；三是（）。
