How does human capital affect economiy?

How does human capital affect economiy? How much does the human brain weigh? human 做主语是单数还是复数?例如：How do human survive How does human survive? how does a good person fulfill his human value how does the expansion of human population affect the animals?中文含义是什么？ how does the action relate to my duty to become an ideal human being who trea 英语翻译1,How much of our body is just water 2,Do you ears and nose continue to grow all your life 3,How much does the human brain weigh?4,How fast do our fingeinails grow? how does it taste? how does it taste How does Lily like? how does it feel how does she do how does Sarah feel how does earthquake happen How does he work how does sb how does aduck grow? how does he look?