English is popular around the world and most people speak it _____ a second language. [ ]

A. as

B. like

C. for

D. by

机体新陈代谢和体温调节活动都必须有水的参与才能完成。每日需水量，婴儿______ml／kg，以后每3岁减去______ml／kg，9岁时______ml／kg，成人______ml／kg。