【单选题】给定如下Java代码,下列( )选项可以加入到Sample类中,并重写amount方法。 c1ass Super { public double amount(double a) { return a*0.8; } } public class Sample extends Super{ }
【简答题】More than 20,000 drivers and front seat passengers are killed or seriously injured each year. At a speed of only 30 miles per hour it is the same as falling from a third floor window. Wearing a seat b...