In modern times we humans face changing conditions.
在現(xiàn)代，我們?nèi)祟惷媾R著不斷變化的條件。
For humans to live, we need clean air and clean water.
為了人類的生存，我們需要干凈的空氣和干凈的水。
Pollution is now a growing problem around the world.
污染在世界各地都是一個日益嚴(yán)重的問題。
Pollution poisons the air and water that we depend on.
污染污染了我們賴以生存的空氣和水。
Polluted air makes people sick and afraid to go outside.
污染的空氣使人們生病，不敢出門。
Polluted water poisons our food supply.
被污染的水污染了我們的食物供應(yīng)。
As a result, we never know which foods are safe to eat.
因此，我們永遠(yuǎn)不知道哪些食物是安全的。
Human beings cannot live in a poisoned environment.
人類不能生活在有毒的環(huán)境中。
Therefore, pollution is a major threat to our existence.
因此，污染是我們生存的一大威脅。
Humans need temperatures to be in a comfortable range.
人類需要一個舒適的溫度范圍。
To be in a comfortable range means to be neither too hot nor too cold.
處于舒適的范圍意味著既不太熱也不太冷。
With global warming, global tempertures are rising.
隨著全球變暖，全球氣溫正在上升。
As temperatures rise, the polar icecaps will melt.
隨著氣溫升高，極地冰蓋將會融化。
As the polar icecaps melt, ocean levels will rise.
隨著極地冰蓋的融化，海平面將會上升。
Areas of some countries will soon be under water.
一些國家的部分地區(qū)將很快被淹沒。
People will be forced to relocate from flooded areas.
人們將被迫從洪水地區(qū)搬遷。
In nature, even small changes can sometimes have large effects.
在自然界中，即使是很小的變化有時也會產(chǎn)生很大的影響。
It's difficult to predict what's going to happen.
很難預(yù)測會發(fā)生什么。
The entire ecosystem that we depend on is changing.
整個生態(tài)系統(tǒng)，我們依賴于正在發(fā)生變化。
Some of these changes are irreversible.
這些改變是不可逆轉(zhuǎn)的。
Irreversible changes cannot be undone.
不可逆轉(zhuǎn)的變化是無法逆轉(zhuǎn)的。
Let's hope the humans are smart enough to understand how the world is changing.
讓我們希望人類足夠聰明，能夠理解世界是如何變化的。
With more understanding ,we can make better choices about what to do.
有了更多的理解，我們可以更好地選擇做什么。
We can face the challenges of pollution and global warming.
我們可以面對污染和全球變暖的挑戰(zhàn)。
We need to do this before it's too late.
我們必須在一切都太遲之前做這件事。
This planet Earth is our only home and we need to protect it.
地球是我們唯一的家園，我們需要保護(hù)它。
