Would you correct my sentences?

Dear native English speakers,
Would you correct mu sentences if needed?
1 Curitiba is located in the southern part of Brazil.
2 Osaka is the third largest city in Japan.
3 Osaka has a population of about 2.7 million as of 2015.
4 The students' ages range from 16 to 21.
5 What is the population of Japan?
6 There are more than twenty thousand immigrants in this city.
7 Curitiba is the seventh largest city in Brazil.

Thanks in advance.

Hirashin

Everything looks correct to me. The only issue is a likely typo in both the title and initial sentence before your example sentences. In both "mu" should be "my".

Maybe he means that they're μ-sentences.

Oh! I didn't notice it. Probably because I was in a hurry when I posted it before going to bed.
Thank you for your help, OoTmaster and Julimaruchan.
If possible, would you see my other posts?