单项选择题

A．The animals over-fertilize the soil.
B．Dead plant roots can’t hold the soil together.
C．The wrong types of plants are left standing.
D．There is a buildup of plant and animal matter.
<上一题 目录 下一题>
热门 试题

填空题
percentage
单项选择题
A．They ran a high fever.B．They died from excessive bleeding.C．Their nervous system was damaged.D．They suffered from heart-attack.
A．They ran a high fever.
B．They died from excessive bleeding.
C．Their nervous system was damaged.
D．They suffered from heart-attack.
相关试题