There are 7 characteristics of Egypt.
1.Stable food supply
2.social structure
3.government
4.religion
5.culture
6.written language
7.technology.
By rename do you mean turn into an improper fraction?
if so, it is because without turning it into an improper fraction, you cannot subtract 3/4 from 1/4 because you would get a negative answer and that would be incorrect
1. geologic time
2. stratum
You could have just googled these...
