What segments are there in the middle of Beijing Mobile's mobile phone number?

There are many middle four digits in Beijing, the most common ones are11,which are found in almost all paragraphs, and there are also 2222,21/kloc-0,265438+. . . . .

Actually, you can't look at the four digits, it should be the top two. The digits in 135 are 0 1, 20,21,22,52, 136 is 0 1, 265438+. 138 has 1 1, 10, 0 1, 139 has 0 1,1.