在木变石中，具有蓝色色调并具有猫眼效应的品种称为虎睛石。
参考答案：错
圆筒形的易拉罐、地球仪、粉笔盒、乒乓球、魔方中，形状类似于棱柱的有（ ）
A．1个
B．2个
C．3个
D．4个
26．Even if there is no scientific proof yet ______ secondhand smoke causes cancer, there is no reason why nonsmokers should be forced to take this risk．
A．which
B．that
C．when
D．Where
