A-A+
The ozone layer (must be protected) because (i
问题详情
The ozone layer (must be protected) because (it) shields the Earth (from) excessive ultra-vilolet (radiations).
A．must protected
B．it
C．from
D．radiations请帮忙给出正确答案和分析，谢谢！
参考答案
正确答案：D
D改为radiation解析：radiation辐射，放射，是不可数名词。
