A:曲线乙变为曲线丙的原因最可能是该种群迁入了大量同种个体
B:曲线乙可用于表示封闭环境中草履虫种群数量的长期动态变化规律
C:甲、乙、丙三条曲线表示的种群数量增长方式都为“J”形增长
D:ab段种群数量相对稳定达到K值,种群出生率约等于死亡率
函数y=2x-1的定义域是-∞,1∪2,5),则其值域为( )
The slavery was____(废除)in the end.
(____)He wants to play baseball.
(____)Tim was so happy because he got a gift.
(____)Why are you wearing a Tshirt?
(____)I am going to the cinema tomorrow.
(____)It's difficult to fly a kite.
计算:(x+3)(x﹣5)﹣x(x﹣2).