— Where was your father when I called you, Tony?

— He ____________ his car.

A．washes

B．washed

C．is washing

D．was washing

组成结肠肠腺的细胞有（）。

A.柱状细胞

B.内分泌细胞

C.杯状细胞

D.干细胞

E.潘氏细胞