I first hear that discuss the zoos are advantage or disadvan

I first hear that discuss the zoos are advantage or disadvantage to protect animals.I have never considered that the zoos are the paradise or the hell for animals.According to the environment pollution and destroy,lots of species die out rapidly in the present age,even if human also have to worry about how to survive in the terrible circumstance.
About the theme,I think that the zoo is neither the Eden of animals in bad environment,nor the lower world in proper living space.Protecting environment is a primary problem to us and it should be developed base on the biology balance.It is said that import a species to a new field without test may be kill out many of animals that living in there.People often bring some animals far from the environment of their living.There are no feasible temperature,humidity,food and natural enemy.These animals only change their second nature adapts to the condition and the form of second nature need plenty time,one or several generations.
这是一个话题讨论：关于动物园是保护动物还是伤害动物。
我只是根据这个问题，写了一些自己的想法。主要是练习英语。主要想请大家帮我改改语法。
我的文章汉语是这个意思：
我第一次听到谈论动物园对保护动物是利还是弊。我以前也没考虑过动物园是动物的天堂还是地狱。随着环境的污染与破坏，最近几年，许多动物快速灭绝，甚至人类也开始担心在这恶劣的环境怎样生存。
对于这个主题，我认为：动物园既不是糟糕环境中的动物的乐园，也不是恶劣环境中的动物的天堂。对于我们，护环境是首要问题并且要基于环境平衡。据说，不经实验的将一个物种引进一个新的环境，将会导致本地的许多物种灭绝。人们经常把动物带到他们的生存环境，那里没有适合的温度，适度，食物与天敌。这些动物只能改变他们的习性，而这些习性的改变需要大量的时间，或几代。

Can you give me some Chinese clues?I cannot figure out what you want to say.
我第一次听到谈论动物园对保护动物是利还是弊.我以前也没考虑过动物园是动物的天堂还是地狱.随着环境的污染与破坏,最近几年,许多动物快速灭绝,甚至人类也开始担心在这恶劣的环境怎样生存.
对于这个主题,我认为：动物园既不是糟糕环境中的动物的乐园,也不是恶劣环境中的动物的天堂.对于我们,护环境是首要问题并且要基于环境平衡.据说,不经实验的将一个物种引进一个新的环境,将会导致本地的许多物种灭绝.人们经常把动物带到他们的生存环境,那里没有适合的温度,适度,食物与天敌.这些动物只能改变他们的习性,而这些习性的改变需要大量的时间,或几代.
Whether the zoo is a paradise or a hell has never come into my consideration until the first time when I heard the discussion of the advantages and disadavantages of protecting animals in zoos.In the past years,the animals have been going into extinction quickly due to the environment pollution and damages.Even human beings have started worrying about the living in such an adverse surrounding.
My opion about this topic is that the zoo is not a paradise or an amusement park of animals in the bad surrounding.As for us,the primary consideration is the environmental protection based on the balance of the surroundings.It is said that introducing one kind of new species into a new environment without any experiments will lead to extinction of many other local species.Animals are often led to live in an environment,where the temperatures and humidity are not right and no food or natural rivals are found.Such animals can only change their habits,which may take plenty of time or up to several generations.