五指并拢时，一只手掌的面积占全身体表面积的比例是（）
A.0.5%
B.1%
C.2%
D.5%
E.9%
参考答案：B
The doctor told Charlie to breathe deeply and ____. [ ]
A. so did Charlie
B. Charlie did so
C. Charlie does so
D. did Charlie so
举例说明作为教育的数学和作为科学的数学之间的差异性。
