反映不同生物之间通过能量流动而连续依赖的非单一次序组成的复杂关系一般被称为()
A.能量网
B.食物链
C.食物网
参考答案:C
– You seem to have made another decision.
---You are right. I am considering ________. California , you know, is my first choice.
A.to move out
B.getting out of here
C.to move my house
D.moving family
(5分)用符号表示或写出符号所表示的意义:
(1)2个钙原子 ;(2)氮气 ;(3)H ;(4)3S2- ;.(5)氩元素