Test and analysis: first find out the irrational number according to its definition, and then solve it according to the frequency method.

There are three irrational numbers,, * * *

The frequency of irrational numbers is 3.275 = 60%.

So choose C.

Comments: The key to solving the problem is to master three forms of irrational numbers: ① infinite numbers, ② infinite acyclic decimals, and ③ inclusive numbers.