对于湿式自动喷水灭火系统,在吊顶下布置喷头时,应采用()喷头。
A.下垂型
B.边墙型
C.直立型
D.水幕
参考答案:A
Mr King, _____ legs were badly hurt, was quickly taken to hospital.
A.who
B.that
C.whom
D.whose
子类的对象拥有其超类的对象的全部属性和方法,称为子类对超类的______。