低速离心机的主要构成包括（）

A.电动机

B.离心转盘（转头）

C.调速装置

D.离心套管

E.真空装置

— Which of these two English books will you borrow?

— I'll borrow _____ of them. Because they are very interesting. [ ]

A. either

B. all

C. neither

D. both