排水塑料管安装时中间伸缩接的间距保持()。 ["2","6","8","10"]
小儿肾病综合征肝肾阴虚证的首选方为() ["真武汤","一贯煎","玉屏风散","六味地黄丸","知柏地黄丸"]
排水管道通球率必须达到()。 ["50%","75%","100%","90%"]
下列中国空军战斗机中,不是由南昌飞机公司制造的是() ["A、初教-5","B、强-5","C、K-8","D、直-8"]
防挂失交易操作风险须注意(). ["申请书的填写人","申请书的填写事项","后续处理的办理者","后续处理的确认"]
曲轴箱有几种结构形式?各有何特点?