继承是Java语言的一个重要机制，所有的Java类都继承自根类( )。
A．Class
B．Object
C．String
D．Date
参考答案：B
解析： 本题考查Java的继承机制。选项A错误，Class类封装了类和对象的属性特征，包含着解释Java类的信息。选项B正确，Object类处于Java类层次结构的最上层，是所有类的父类。也就是说，所有Java语言中的类都是直接或间接继承Object类得到的。选项C错误， String类是字符串类，用于构造字符串常量。选项D错误，Date类是日期类，提供了处理日期、时间的多种方法。
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| A teacher started his first job at a primary school and wanted to make a good impression (印象) on the children. When he noticed a boy 1 all by himself, 2 the other children were playing football, he walked up to him and asked, "Are you alright?" The boy told him 3 was fine and the teacher left him. A few minutes later, 4 , he noticed that the boy was still standing alone and had not 5 he other boys. This time, the teacher decided to 6 what was wrong. He came up to the boy again and said, "Hi, are 7 you're not feeling left out? Would you like me to be your friend?" The boy 8 uncomfortable, but after a little hesitation (犹豫), he said, "Maybe". Encouraged by his progress, the teacher asked,"Tell me, 9 are you standing here alone?" "Because," the said with clear anger in his 10 , "I'm the goalkeeper." | ||||
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