撞【zhuàng】
1. bump; ram; hit 2. run into; meet by accident 3. rash; dash
[动]1、两物相碰 2、无意碰见 3、闯,猛冲或突然直下

笨拙的男孩撞到了桌子。
The clumsy boy bumped into the table.

在街的拐角处,我撞见了我的老同学。
I run into an old classmate at the corner of the street.

公交车失控了,在马路上横冲直撞。
The bus is out of control and is rampaging about wildly.
追【zhuī】
1. chase after; pursue 2. trace; look into 3. court; woo; pursue
[动]1、加快速度赶上 2、事后调查 3、努力达到目的

孩子追着蝴蝶跑。
The children are chasing after the butterflies.

我们要把事情发生的原因追查清楚。
We must look into the cause of the incident.

李教授不追名逐利,潜心做研究。
Professor Li devotes himself to the study and has no desire for personal fame and gain.
追查【zhuī chá】
investigate; track down (information); find out
[动]追究查问;事后调查

这起重大安全事故,必须追查责任。
The responsibility for this catastrophic accident must be found out.