我喜欢这个城市，因为这里很安静。

Wǒ xǐhuān zhè gè chéngshì, yīnwèi zhèlǐ hěn ānjìng.

I like this city because it is very quiet here.

请大家先安静一下，老师要说话了。

Qǐng dàjiā xiān ānjìng yíxià, lǎoshī yào shuōhuà le.

Everyone please be quiet for a moment; the teacher is going to speak.

晚上出门要注意安全，最好跟朋友一起走。

Wǎnshang chūmén yào zhùyì ānquán, zuìhǎo gēn péngyou yìqǐ zǒu.

Be careful about safety when going out at night; it's best to walk with friends.