Having taken our seats, _______.  [ ]

A. the professor began the lecture  

B. the lecture began soon 

C. we were attracted by the lecture soon 

D. the bell announced the beginning of the lecture

建筑安装工程费由( )组成。

A．直接工程费、间接费、计划利润和税金

B．直接工程费、间接费、法定利润和税金

C．直接费、间接费、计划利润和税金

D．直接费、间接费、利润和税金