在大自然中散步，我的心情就会好起来。

Zài dàzìrán zhōng sànbù, wǒ de xīnqíng jiù huì hǎo qǐlái.

When I walk in nature, my mood becomes better.

很多孩子在城市长大，很少接近大自然。

Hěn duō háizi zài chéngshì zhǎngdà, hěn shǎo jiējìn dàzìrán.

Many children grow up in the city and rarely get close to nature.

我们要学会爱护大自然，不乱扔垃圾。

Wǒmen yào xuéhuì àihù dàzìrán, bù luàn rēng lājī.

We must learn to protect nature and not throw rubbish around.