—Could you tell me ______?

—Of course, last night.

A．when you reached our town

B．when did you reach our town

C．how you came to our village

D．how did you come to our village

右图是某一动物物种迁入一个适宜环境后的增长曲线图，请据图回答下列问题：

由图可知，第6年后种群数量趋于稳定。阻碍种群继续增长的环境因素可能包括（）。