缺磷时,老叶先出现症状,叶色浅黄。
参考答案:错
The population is grow fast. In hundreds of years, there will be only _____ on the earth. [ ]
A. room to stand
B. room to stand in
C. a room to stand in
D. a room to stand in
森林的控制洪水、调节水流功能称为()
A.渗水功能
B.吐水功能
C.吸水功能
D.理水功能