单项选择题
A.7B.26C.28D.29
A.P1=P2B.P1>P2C.P1<P2D.无法确定
A.4/45B.2/45C.1/45D.1/90
A.20B.10C.15D.16
A.1/3B.1/6C.1/9D.1/27
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