Kind neighbor

Remembering that there was an elementary school near his house, he carried two-heavy futons and hung them on the fence of the school. Mr. Inuyama went to the movies. After he finished watching it, it started raining. He was anxious about futon which may get soaking wet. Hurrying to the school, he was surprised that the futons was were gone. Rushing into the police station, he reported this.The officer thought a thief broke into his house. Then he explained that the futons hung on the fence was were stolen. The officer laughed and said. "Someone living near the elementary school must have taken your futons."

Throughout the above there is only a couple of mistakes. The first is using the correct article before nouns. The second most recurring mistake is the use of plural. the story begins talking about two futons but ends up talking about just one. One last thing to note is futon had a capital 'F' in some instances. 

It may seem like a lot is highlighted but it is just the same kind of mistake repeated so your writing here is actually very good. 

Going back to the school, he visited the house which is right next to the school. The parson person was kind enough to take his futon. He was relieved to find his futons and said thank you. Two months later, he decided to dry the futon again. He didn't want to bother those who were living near the school so he pick the sunny day which wasn't supposed to rain and he dried futon near his house. Then he went out. But unlike the forecast, it started raining. Hurrying back to the place, he was about to take the futon. However, the futon was gone again. Visiting the nearest house, ringing the bell, he asked the person whether he knew anything about futon. The person said that he took the futon since it started raining. Mr. Inuyama really appreciated what his neighbors did and said thank you from bottom of his heart.

This second paragraph is much more consistent. One thing to bear in mind is the use of articles such as "the" and "a". 

I also added the word "were" highlighted above to show that the action was an ongoing action at the time of the story.

This is a very good piece of writing with just a few small mistakes, well done! Keep it up!

Taking part in Model United Nations

Last year, I took part in a meeting of Model United Nations for the first time.
The nameplate of the country Zaire was assigned to me.So I should speak for Zaire at the meeting.Before that, I found some information about Zaire on the Internet.At the meeting,however,they opened the topics that I didn't hadn't found information about.And there were many senior high school students.And just a few junior high school students like me.I was too nervous and shy to speak,even though the first half was in Chinese.My schoolmates were braver than me.They spoke many times.
In the second half, every each country delegate's language should change into English.So there were fewer people speaking.I finally decided to speak.I put my hand up.And the chair added me into the speaking list.However, it was so late that I was the last one to speak.I mainly talked about general situation and asked the developed countries for help.when the time given was over, I had not finished my words speaking but I had to stop.
Though I spoke little in the meeting, I still felt excited.I would will continue studying hard to improve my English.

This is really good. The words I've crossed out and changed are ways to make the language flow more like a native speaker, which is something you'll pick over time. This was a very well written piece of English.

Speaking in front of a large group of people must have been very difficult, especially in a foreign language. Well done!

Milk 牛奶

I am 19 years old now,I will drink a glass of milk every night.At first it was because I was short when I was a child,and my mother was anxious to make me grow taller（who had required me to drink heated fresh blood of male chicken）,then I drank milk from junior high school.Now I am 180 centimeters tall（mom,thank you）,there is not much hope grows for growing taller,but drinking milk seems to become a habit.By the way,I like drink with chocolate pie.
我今年19岁，每晚都会喝一杯牛奶。起初是因为我小时候比较矮，我妈急着让我长高(让我喝过雄鸡血)，就从初中开始喝牛奶了。现在我1米8(老妈，多谢啦)，不太可能再长高了，但是喝牛奶好像已经成了一种习惯。对了，我喜欢配着巧克力派吃。

This is very good, the only errors were in using the continuos forms of verbs towards the end.

When speaking about a continuos action that is done over a long period of time such as 'drinking milk', we use the continuous form of the verb, in this case 'drink' becomes 'drinking'.

other examples could be 'I enjoy swimming', changing the verb 'swim' to 'swimming'.

or 'climbing is fun', changing the verb 'climb' to 'climbing'.

Other than that though, very good.

 

すみません、思い知りました。 「鮮明」は形容詞そして「アリアリ」は副詞。