Having finished her project ,she was invited by the school______ to the new students.

A．speaking

B．having spoken

C．to speak

D．to have spoken

建立交叉分组表的通常做法是将各种不同变量划分为（）。

A.逻辑变量

B.定性变量

C.定量变量

D.自变量

E.因变量