没有_________,自然界的碳、氧相对平衡难以维持。
绿色植物
(2013·临淄期末联考) It's too late. Go to bed right away.Forget you need to get up as early as you can ________ the early train?
A.catch
B.catching
C.caught
D.to catch
健康成人24小时尿中排出蛋白总量为
A.0~150mg
B.150~200mg
C.200~250mg
D.250~300mg
E.300~400mg