等级资料比较的假设检验宜用（）
A.t检验
B.u检验
C.F检验
D.秩和检验
E.四格表χ2检验
参考答案：D
把下面各数从小到大排列．0.7、0.701、0.71、1.7、0.711、7.1．
The medical team, three doctors and two nurses, _______ for the mountain area yesterday.
A．put off
B．put up
C．set about
D．set off
