离心式鼓风机轴承的作用是什么？

在手指末端交接的经脉是

A．手之阳经与手之阴经
B．手之阳经与足之阳经
C．手之阴经与足之阴经
D．足之阳经与足之阴经
E．手之阳经与足之阴经

Some of the artist’s paintings are __________ in this exhibition in our City Museum.

A．in turn

B．in public

C．on display

D．on duty

—_______ is the meeting room, Mrs. Smith?  —It’s about 20 meters long and 10 meters wide.

A．How big

B．How far

C．How tall

D．How long

简述弗洛伊德学说中的两个基本命题。