我在街上碰到我的朋友。
wǒzài jiēshàng pèngdào wǒde péngyǒu 。
I ran into my friend on the street.
我不想在考试中碰到难题。
wǒ bùxiǎng zài kǎoshì zhōng pèngdào nántí 。
I don't want to bump into difficult questions during the exam.
昨天我碰到一个老同学。
zuótiān wǒ pèngdào yígè lǎo tóngxué 。
Yesterday, I met an old classmate.