Lee Pickett, CFA. a well-known and respected analyst, follows the computer industry and does research about types of measurement scales. Pickett categorizes a group of stocks into quartiles based on historical rate of returns. Pickett's approach is most consistent with which type of the following measurement scales（）

A. Nominal.

B. Ratio.

C. Ordinal.

大型永久结构混凝土不得用（）拌制。

A.机械

B.人工

C.现场

D.添加外加剂