For instance , in physics , if you want to understand the arc of a parabola , you shoot a cannon 100 times and see where the cannonballs land .

例如，在物理学里，如果你想要研究抛物线轨迹，你可以发射大炮100次，看看炮弹会落在哪里。

Bombs and cannonballs rained upon the town .

炸弹和炮弹雨点般地落进那个市镇。

And they work very well for billiard balls and cannonballs and gravity .

不论是台球、炮弹，重力，它都能解释的很好。

Whenever the film lets go with an action sequence , though , it 's time to be grateful for computer animation , and to keep both eyes peeled for incoming cannonballs .

不过每当片中出现动作镜头时，你就该感谢电脑动画技术，然后睁大双眼看那些扑面而来的炮弹。