学前儿童能力筛查（50项）可用于幼儿园儿童入园筛查。
参考答案：错
解方程：5x+2=3x2
To prevent the air ___ ,something will have to ___.
A．to pollute…take
B．from being polluted ..be done
C．to be polluted…be taken
D．from polluted… be done
