【简答题】为了明确表示子类中的方法是与父类同名的方法,在子类的方法返回值前面加上 关键字。
【单选题】听力原文:Migratory birds use several ways to help them navigate. While traveling on a clear night they use the stars as guides. On cloudy nights, they may be using the earth's magnetic field or the wind t...
【单选题】Most birds find it safe to sleep in the trees, but they have eggs or young chicks, they don't use a nest. [ ]
【单选题】—How do people do bird-watching? —Sometimes they______the birds quietly, sometimes they use telescopes.