采用石灰桩时，下述（）不正确。（）

A.当生石灰用量超过30%时，石灰桩的强度较大

B.一般采用生石灰与掺和料的体积比为1：1或1：2

C.石灰桩空口高度不宜小于500mm，这是因为要保持一定的覆盖压力，防止石灰桩膨胀时上鼓

D.计算石灰桩面积时，桩径可取单孔平均成孔直径

All of the following are advantages of using price/sales (P/S) multiple EXCEPT:（）

A. Sales figures are not as easy to manipulate as earnings and book value, which are significantly affected by accounting conventions.

B. P/S multiples are more reliable because sales data cannot be distorted by management.

C. P/S multiples provide a meaningful framework for evaluating distressed firms.