Why is RATIO in plural?
In China skewed sex ratios mean that a prospective bridegroom must own an apartment and shower his future in-laws with cash. But a glittering stone goes to the woman, not her family.

http://www.toutiao.com/i6422991579501298177/

Question

Why is RATIO in plural?
In China skewed sex ratios mean that a prospective bridegroom must own an apartment and shower his future in-laws with cash. But a glittering stone goes to the woman, not her family.

http://www.toutiao.com/i6422991579501298177/

Answer

The writer may have been thinking of different ratios at different times of history. If he or she was thinking only of one ratio - the one between men and women generally - then he or she should have said "ratio".

Answer

COS HE'S TALKING ABOUT AT LEAST  TWO RATIOS