单项选择题
A.25%-35%B.高于35%C.低于15%D.15%-25%
A.1/4B.3/8C.1/2D.5/8
A.1/5B.2/5C.3/4D.3/10
A.4B.5C.6D.7
A.240B.6000C.10080D.120
A.7B.8C.9D.10
A.14B.15C.18D.21
A.36B.50C.100D.400
A.6种B.8种C.9种D.12种
A.2519B.2520C.5039D.5040
A.75B.82C.88D.95