问题 单项选择题

根据所给出的结果和对应到实数空间的函数取值范围,随机变量分为()。

A.确定型随机变量和不确定型随机变量

B.跳跃型随机变量和连续型随机变量

C.离散型随机变量和跳跃型随机变量

D.离散型随机变量和连续型随机变量

答案

参考答案:D

解析:根据所给出的结果和对应到实数空间的函数取值范围,随机变量一般分为离散型和连续型。离散型随机变量是随机变量X的所有可能值只有有限个或可列多个;连续型随机变量是随机变量所有可能值由一个或者若干个(有限或无限)实数轴上的区间组成。

判断题
完形填空

请根据以下的任务说明和写作要求,以We Cannot Do without Gratitude 为题写一篇150字左右的英语短文,在校园英文小报上的Hot Topic栏目发表。

[任务说明]

“感激”是每个人都应该懂得的一种待人接物的态度。请认真阅读下面的短文,然后完成以下写作任务。

1.概括故事的内容要点,以此引入话题,该部分的词数大约30;

2.就“感激”这个主题发表你的看法,至少包含以下内容要点:

1)什么是感激(gratitude)?

2)感激的表现方式。

3)表达感激最重要在于真诚(sincere)。

4)故事的启示和你的结论。

[写作要求]

1.你可以使用实例或其他论述方法支持你的论点,也可以参照阅读材料的内容,但不要抄袭阅读材料中的句子。

2.短文的开头已给出,不计入所限字数。短文开头:

The other day I read a story which is about …

[阅读材料]

As I got into a taxi one afternoon, the driver was very angry about something that had happened to him earlier that day. Here’s how he told the story:

“One of my fares (旅客) left a wallet in my cab this morning. Nearly three hundred dollars in it. I spent more than an hour trying to trace the guy. Finally I found him at his hotel. He took the wallet without a word and glared at me as though I’d meant to steal it.”

“He didn’t give you a reward?” I asked.

“Not a cent. But it wasn’t the money I wanted,” he fumbled, then exploded, “If the guy had only said something…”

Why was the driver so upset? All he wanted was something simple, but even more valuable than money: to be thanked for his efforts. In short, what he wanted, what he needed but did not get, was a little bit of gratitude.