原文： Is that all? A:I want some envelopes ,please? B:Do you want the large size or small size? A:The large size , please. B:Do you have any writing paper? A:Yes I do. I don't have any some pads. I only have large one. Do you want a pad? B:Yes,please.
原文： A pleasant climate. A:Where do you come frome? B:I come from Greece. A:What's the climate like in your country? B:It's very pleasant. A:What's the weather like in spring? B:It's often windy in March. It' always warm in April
原文： Hurry up！ A:Can you make the tea,Sam? B:Yes,of course I can ,Penny. Is there any water in this kettle? A:Yes ,there is. B:Where is the tea? A:It's over there behind the teapot. Can you see it? B:I can see the teapot ,but I can't see the tea.
原文：How do ;you do? A:Come and meet our employees,Mr.B. B:Thank you Mr.A. A:This is ...and this is .... . B:How do you do?. Those women are very hard-working. What are their jobs? A:They are keyboard operators. A:This is .. and this is .. . B:How do you
原文：A new dress. A:What color's your new dress? B:It' green.Come upstairs and see it. A:Thank you. B:Look,here it is. A:That's a nice dress.It's very smart. B:My hat's new too. A:What colour is it? B:It's the same colour,it�
Can you help me,please? Sure,What can I do for you? I'm looking for a gift for my son's birthday. How about this video game? That's a good idea.Can you gift-wrap it,please？ Sure.No problem. Excuse me,ma'am. Do you have a blue dress m
一、进程和线程 进程是一个运行起来的可执行程序。进程有三种状态： 就绪 进程获得了除了CPU外所有必要资源 运行 进程获得了所有资源，开始执行 阻塞 进程正在尚未满足要求，正在等待 线程是程序执行流的最小单位（要执行，最起码是一个线程） 二、线程和进程的联系和线程一些常识 2.1
2.5 字符串 --- 字符串是不可变的。 1 >>> str = "Hello world!" 2 >>> str[-6:-1] = "python" 3 Traceback (most recent call last): 4 File "<stdin>", line 1, in <module> 5 TypeError: 'str' object does
lesson 040 —— 面向对象简介 关于面向对象的简单介绍。 三大编程范式 面向过程编程 函数式编程 面向对象编程 面向对象概念 类： 把一类事物相同的特征和动作整合到一起就是类。类是一个抽象的概念。类是一种数据结构。 对象：就是基于类而创建的一个具体的事物（具体存在的），也是特征
2.0 数据结构 --- 数据结构是以某种方式组合起来的数据元素集合。 --- python的常见的数据结构 2.1 序列（sequence） --- 序列中的每个元素都有编号，即索引（也称为下标）。 --- 第一个位置索引为0，第二为1，依次类推。也可用负索引，末尾位置为-1，倒数第二为-2，依次类推。 --- 元组是一种特殊
1.5 模块 模块可视为扩展，通过将其导入可以扩展python的功能。python中自带有一组模块，也称为“标准库”。 1.5.1 模块的导入：import + 模块名称 • 使用关键字import导入模块 • import之后跟模块名称，可一次导入多个模块，多个模块名称之间使用逗号隔开 • 使用“模块名称.函数名称
1.1常见难记的几种运算符 1.1.1 除运算 ‘/’ 除运算的结果为小数，即浮点数。 >>> 10/3 3.3333333333333335 >>> 10/2 5.0 >>> 1.1.2 整除运算 ‘//’ （1）整数的整除运算 >>> 10//3 3 >>> 10//2 5 >>> 1//2 0 >>> （2）浮点数的整除运算 1 >>> 1
