Everyone laughed when he _____ the teacher so well.

A. Hardly had Paul realized he was on the wrong flight when the plane took off

B. It was not until the plane had taken off, did Paul realize he was on the wrong flight.

C. Not until the plane had taken off, did Paul realize he was on the wrong fl

D. No sooner had the plane taken off than Paul had realized he was on the wrong flight.

A. As know as far

B. As far as is known   

C. It is known as far

D. Known as far as it is

A. What the lecturer wrote and said was too difficult for me to understand.

B. I found it very difficult to understand what the lecturer said in his book

C. I would have understood what the lecturer was saying if I had read his book

D. The lecturer’s book which I had not read was difficult to understand

A. unconvinced 

B. discharged

C. liberated

D. acquitted

A. dry-cleaning

B. spin-dried

C. spring-cleaned

D. clean dried

A. disabling

B. vexatious

C. dangerous

D. irreparable