A-A+
The ecological balance depends onA．the preserv
问题详情
The ecological balance depends on
A．the preservation of environment.
B．plants and animals.
C．the introduction of a variety of species.
D．natural resources.
参考答案
正确答案：A
解析：细节题。根据第二段提到的“When an environment is undisturbed，the ecology of an area is in balance．”(在环境不受破坏的情况下，这一地区的生态就处于一种平衡状态。)可以看出生态平衡取决于环境的保护，故选A
