医生说，适当的运动和睡眠有利于保持大脑的智力水平。

Yīshēng shuō, shìdàng de yùndòng hé shuìmián yǒulìyú bǎochí dànǎo de zhìlì shuǐpíng.

The doctor said that proper exercise and sleep help maintain the brain's level of intelligence.

智力并不是决定成功的唯一因素，努力和机会也很重要。

Zhìlì bìng bú shì juédìng chénggōng de wéiyī yīnsù, nǔlì hé jīhuì yě hěn zhòngyào.

Intelligence is not the only factor that determines success; hard work and opportunity are also important.

这个游戏可以锻炼孩子的智力。

Zhège yóuxì kěyǐ duànliàn háizi de zhìlì.

This game can train children's intelligence.