更正一下，大多数体力劳动是由男性干的，因为生理上男性在体力方面更有优势。其他工作看上去男性更占优势，是因为在就业市场上男性受到的歧视更少一些。空姐、护士这些工作大多是为了高薪或者养家糊口，？而不是为了婚姻。确实纯粹为了爱职业的很少。
To correct, most manual work is done by men, because biologically men are more physically superior. Other jobs appear to be more male-dominated because men are less discriminated against in the job market.