原式=5-2-27
=-24.
大量的野生生物价值还未开发,这些生物也许在提取药物、改良品种等方面有重要作用,这体现了生物多样的 [ ]
A.潜在价值
B.直接价值
C.间接价值
D.无价值
— It’s very kind Betty to give us a hand.
— That’s true. We should thank her helping us out.
A.for; for
B.of; for
C.for; of
D.of; of