英訳添削お願いします。素人文で読みにくいかと思いますが宜しくお願いします

英訳の添削お願いします。
素人なので誤訳が多く読みにくいかもしれませんが、直していただけたらありがたいです。
よろしくお願いします＃

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日本人が世界最長寿を享受しているのは、ごく最近のこと。
It is just these days that a Japanese is the world most longevity.

60歳まで生き延びるのは200人に1人。子供の3人に2人は7歳以下で死んでいた。
the number of people who survive over 60 years old is only one for 200.
Two third of children die less than 7 years old.

若いうちに多くの人が死んだのは、感染症や飢餓、戦争が主な原因だったと考えられている。
The main reason why many people died so young is infectious disease, starvation, and war.

再び平均寿命が30歳を越えた。
戦後初めて平均寿命が50歳を超える。
Life expectancy exceeded 30 years old again.
Life expectancy exceeded 50 years old for the first time after the WW2.

戦後50年の間に30歳も平均寿命が延びる。
Life expectancy is prolonged for 30 years old after the WW2 during 50 years.

昔の時代は「人生50年」とよく言われているが、実際に「人生50年」になったのは、50年前になって初めて。
It is often said long time ago that "life prolong 50 years.“ but it is the first time that "life is 50 years" is real.

世界中で、現在70歳以上の平均寿命を有するのは、中国、韓国、オーストラリア、ヨーロッパ諸国、アメリカ、カナダなどである。
the country which has a life expectancy older than 70 years old is China, Korea, Australia, European countries, U.S.A., Canada all over the world.

アジア大陸やアフリカ大陸、中南米アメリカのほとんどの国は、平均寿命が60歳以下である。
In the Asian Continent, the African Continent, and most countries of Central and South America's life expectancy is less than 60 years old.

特に、アフリカのシエラレオネは34歳、ザンビアは37歳であり、先進諸国の寿命の二分の一以下である。
Sierra Leone's life expectancy is 34 years old; Zambia's is 37 years old.
these score is a half of developed nations.

No.1 ベストアンサー 回答者： noname#181603 回答日時： 2009/01/09 21:39

とりあえずですが、下記のように書いてみました。

Japan has become the world's top country for longevity only recently.
Chances of living to age 60 were 0.5%.
The chance of living to age 60 is one out of two hundreds / one in two hundreds
Two out of three children died before their 8th birthday.
＞The main reason why many people died so young is infectious disease, starvation, and war.
The main reason of this is thought to be infectious deseases, starvation, and the war.
＞Life expectancy exceeded 50 years old for the first time after the WW2.
Life expectancy exceeded 50 years old for the first time since WW2.
＞Life expectancy is prolonged for 30 years old after the WW2 during 50 years.
Life expectancy was prolonged by 30 years old during 50 years after the WW2.
＞昔の時代は「人生50年」とよく言われているが、実際に「人生50年」になったのは、50年前になって初めて。
＞It is often said long time ago that "life prolong 50 years.“ but it is the first time that "life is 50 years" is real.
Since olden days, it was said that life is 50 years , but it only became real 50 years ago.
＞the country which has a life expectancy older than 70 years old is China, Korea, Australia, European countries, U.S.A., Canada all over the world.
Coutries that have an average life expectany of over 70 years are China, ......, and Canada.
＞In the Asian Continent, the African Continent, and most countries of Central and South America's life expectancy is less than 60 years old.
In the Asian Continent, the African Continent, and most countries of Central and South America, their life expectancies are below 60 years.
＞Sierra Leone's life expectancy is 34 years old; Zambia's is 37 years old. these score is a half of developed nations.
Sierra Leone's life expectancy is 34 years old; Zambia's is 37 years old. Both are below half of that of developed nations.