Cataracts are steep rapids formed by cliffs and boulders inside a river
A cataract is when the lense in your eye starts to turn foggy and opaque so you cannot see very well. you can have an operation to get rid of it where the lense is changed. and... well i guess u no wat a waterfall is...... Wrong. A catarct is also known as a Large or giant waterfall and a waterfall is exactly the same I guess!
i don't know when Nubia existed and i need to know for a class project and i dont know where to find it so if anyone could tell me that would be great. thanks.