To protect the earth in Engpsh, we can say "conserve the earth" or "preserve the earth." These phrases come from the Latin words "conservare" and "preservare," which mean "to keep, protect, or preserve."

Here are some examples of these phrases in Engpsh with Chinese translations:

"We need to take action to conserve the earth's natural resources." (我们需要采取行动来保护地球的自然资源。)
"It's important for us to preserve the earth for future generations." (对我们来说，保护地球以供未来的生命使用是非常重要的。)
"By reducing our carbon emissions, we can do our part to protect the earth." (通过减少我们的碳排放，我们可以尽自己的一份力量来保护地球。)