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
練習冊系列答案
相關(guān)習題

科目：高中英語 來源：同步題 題型：單選題

Only __________according to the directions can the medicine be quite effective.    
[     ]
A. taking                        
B. taken    
C. being tak'en                  
D. having been taken

查看答案和解析>>

同步練習冊答案