在各学段中，《数学课程标准》安排了（）个学习领域。
A、三个
B、四个
C、五个
D、不确定
参考答案：B
The man put on his glasses __________ see clearly.[ ]
A. that
B. so that to
C. in order that
D. in order to
掩蔽效应
