单个样品量足够的随机对照试验结果属于（）
A．一级证据
B．二级证据
C．三级证据
D．四级证据
E．五级证据
参考答案：B
Mike a great day last weekend. [ ]
A. have
B. had
C. has
Tom can't _____. [ ]
A. dances
B. dancing
C. dance
D. to dance
