it's 1) the weather, 2) diet. also personal hygiene
habits.
You only need to smell 4 x to prove this.
to test no.1, go to china, smell one from Fujian and one from
Heilongjiang.
to test no.2, don't have to travel, smell one from malay or
indian and one from chinese.
or maybe singaporean girls always wet down there, so need more
cleaning.
