导入:
第1段:提出一种现象或某种困难作为议论的话题
正文:
第2段:Many ways can help to solve this serious problem, but the following may be most effective. First of all... Another way to solve the problem is ... Finally...(列出2~3个解决此类问题的办法
结论:
第3段:These are not the best but the only two/ three measures we can take. But it should be noted that we should take action to...(强调解决此类问题的根本方法
I was born in a beautiful town with high mountains around it.The mountains are covered with all kinds of green bamboo.Through the town runs a small stream.It’s said that a new railway is going to be built to the east of the town and a bamboo factory to the west.All the children of the school age can go to school.If anyone is ill,he can go to see the doctor in the newly-built hospital.People in the town are hard-working and never take the backwardness lying down.Though they are having a richer and better life,they are not satisfied with what they have got.They are working hard to build their town into a modern one.
导入:
第1段:提出一种现象或某个决定作为议论的话题
As a student, I am strongly in favour of the decision. (亮明自己的观点是赞成还是反对
The reasons for this may be listed as follows. (过渡句,承上启下
正文:
第2段:First of all... Secondly... Besides...(列出2~3个赞成或反对的`理由
结论:
第3段:In conclusion, I believe that... (照应第1段,构成\"总—分—总\"结构
1。 头绪分明,脉络清楚
写好记叙文,首先要头绪分明,脉络清楚,明确文章要求写什么。要对所写的事件或人物进行分析,弄清事件发生、发展一直到结束的整个过程,然后再收集选取素材。这些素材都应该跟上述五个“ W ”和一个“ H ”有关。尽管不是每篇记叙文里都必须包括这些“ W ”和“ H ”,但动笔之前,围绕五个“ W ”和“ H ”进行构思是必不可少的。
2。 突出中心,详略得当
在文章的框架确定后,对支持故事的素材的选取是很关键的。选材要注意取舍,应该从表现文章主题的需要出发,分清主次,定好详略。要突出重点,详写细述那些能表现文章主题的重要情节,略写粗述那么非关键的次要情节。面面俱到反而使情节罗列化,使人不得要领。这一点是写好记叙文要解决的一个基本问题,也需要一定的技巧。如:
One night a man came to our house and told me, "There is a family with eight children。 They have not eaten for days。" I took some food with me and went。
When I finally came to that family, I saw the faces of those little children disfigured (破坏外貌) by hunger。 There was no sorrow or sadness in their faces, just the deep pain of hunger。
I gave the rice to the mother。 She divided the rice in two, and went out, carrying half the rice。 When she came back, I asked her, "Where did you go?" she gave me this simple answer, "To my neighbors — they are hungry also!"
3。 用活语言,准确生动
记叙文要用具体的事件和生动的语言对人、事、物加以叙述。一篇好的记叙文的语言既要准确、生动,又要表现力强,这样才能把人、事描写得具体生动,其可读性才强。试比较下面一篇例文修改的前后效果。
原文:
One day Xiaoqiang was wandering away。 He was soon lost among people and traffic。 He could not find the way back home and started crying。 Just then, two young students who were passing by found him standing alone in front of a shop and crying。 They went up to Xiaoqiang and asked him what had happened。 Xiaoqiang told them how he got lost and where he lived。 The two students decided to take him home。 Mother was pleased to see Xiaoqiang come back safe and sound。 She invited the two students into the house and gave them some money, but they didn't take it。 She served them with tea but they left。
修改后:
The other day, five-year-old Xiaoqiang left home alone and wandered happily in the street。 After some time, he felt hungry so he wanted to go back home。 But he found he was lost among the crowded people and heavy traffic。 When he could not find the way home, he started and crying。 Just then, two young students who were passing by from school found him sanding crying in front of a shop。 They immediately went up to him。
"Little boy, why are you standing here crying?" they asked。
"I want Mom, I go home。" said the boy, still crying。
"Don't worry, we'll send you home。"
And they spent the next two hours looking for the boy's house。 With the help of a policeman, they finally found it。
When the worried mother saw her son come back safe and sound, she was so thankful and she invited the students into her house。 Gratefully, she offered them some money, saying it was a way to express her thanks, but the young students firmly refused it and left without even a cup of tea。
导入:
第1段:Recently we’ve had a discussion about whether we should... (导入话题
Our opinions are divided on this topic.(观点有分歧
正文:
第2段:Most of the students are in favour of it.(正方观点
Here are the reasons. First... Second... Finally...(列出2~3个赞成的理由
第3段:However, the others are strongly against it. (反方观点
Their reasons are as follows. In the first place... What’s more... In addition...(列出2~3个反对的理由
结论:
第4段:Personally speaking, the advantages overweigh the disadvantages, for it will do us more harm than good, so I support it.(个人观点 オ
C语言while、do-while、for循环课程5
课程3中,提到C语言基本语句分为:数据定义语句,数据处理语句
数据处理语句又可分为:表达式语句,函数调用语句,空语句(;,复合语句,流程控制语句。
流程控制:指程序代码执行的顺序。流程的分类:顺序、选择、循环。
C语言的循环结构通过三种语句来实现,即while、do-while、forWhile语句的一般形式while(循环条件表达式循环体语句;
功能:当循环条件表达式为真,执行循环体语句,执行完了,再判断条件表达式是否为真,为真,则再执行,直到条件表达式为假时,退出while循环。
实例1:用while语句求1~100的累加和。
#include//C语言编译预处理命令,文件包含为stdio.h
voidmain(//至少有一个用main(命名的主函数,返回值为void无值类型{
inti=1,sum=0;/*初始化循环,定义变量i和累加器sum,定义和之前,累加器清零*/
while(i<=100
{
sum+=i;//sum+=i是一个复合赋值运算符,等价于sun=sun+i;i++;
}
printf("1+2+3+...+100=%d ",sum;//输出十进制数,1加到100累加器的和}
MicrosoftVisualC++6.0运行结果
使用while循环时,一定要对循环条件表达式中出现的变量提前赋值,并在循环体内修改有关变量的值,以使循环能趋于终止。
While循环为当型循环,do-while循环也叫直到型循环。
do-while语句的一般形式为:
do
{
循环体语句}while(
循环条件表达式
实例2:用do-while编制一个求n!的程序,n的值由键盘输入。
#include
voidmain(
{inti=1,n,p=1;
printf("请从键盘输入一个数,进行连乘积: ";
scanf("%d",&n;
do
{p=p*i;
i++;
}while(i<=n;
printf("连乘积的结果为p=n!:%d ",p;
}
分析:此程序,先定义三个变量i、n、p,p从p乘1开始执行,再i进行自增1,循环体中的语句执行完毕后,判断while的循环条件表达式,当i自增1为2时,看2是否<=输入的n值,若为真,则继续返回do循环,直到i自增的值比n大,则退出循环。
do-while主要用于人机交互,do-while循环是先执行后判断,do里面的循环体至少被执行一次。区别于while是先判断循环条件表达式,后执行。
for循环也叫步长型循环
一般格式:for(表达式1;表达式2;表达式3循环体语句;
功能:先执行表达式1,再执行表达式2,如果表达式2的值为真,就执行循环体语句,最后执行表达式3.完成一次循环后,从表达式2执行,直到表达式2为假,退出循环。
实例3:参考实例1,用while求1~100的累加和,现在用for语句求1~100的累
加和。
#include
intmain(void
{
inti;intsum=0;
/*初始化循环,定义变量i
和累加器sum,定义和之前,累加器清零*/
for(i=1;i<=100;i++
{
sum=sum+i;
}
printf("sum=%d ",sum;
return0;
}
实例4:爱因斯坦的`阶梯问题:有一个长阶梯,若每步上2阶,最后剩1阶;若每步上3阶,最后剩2阶;若每步上5阶,最后剩4阶;若每步上6阶,最后剩5阶;只有每步上7阶,最后刚好一阶也不剩。请问该阶梯至少有多少阶。编写一个C程序解决该问题。
#include
main(
{intx;
for(x=7;;x+=7
if(x%3==2&&x%5==4&&x%6==5
break;
printf("Thenumberoftheladdersis:%d ",x;
}
分析:发现x一定是7的整数倍,可以依次递增地求出7的整数倍的值(7*1、7*2、7*3……),每求出一值,就用该值与2、3、5、6进行取模运算,最先得到的满足上述5个方程式的x值即为本题的答案。
用while语句,简单快速实现爱因斯坦的阶梯问题
#include
intmain(
{
inti=1;/*i为所设的阶梯数*/
while(!((i%2==1&&(i%3==2&&(i%5==4&&(i%6==5&&(i%7==0
++i;/*满足一组同余式的判别*/
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