保证

我向你保证，明天一定按时完成。

wǒ xiàng nǐ bǎo zhèng, míng tiān yí dìng àn shí wán chéng.

I assure you, tomorrow it will definitely be completed on time.

我保证，以后不迟到了。

wǒ bǎo zhèng, yǐ hòu bù chí dào le.

I promise I won't be late again.

努力是取得成功的保证。

nǔ lì shì qǔ dé chéng gōng de bǎo zhèng.

Effort is the guarantee of success.