A．Were it not B．If it was notC．Had it not been forD．Had……

单项选择题At first Tim insisted he was right, but then began to ______.

单项选择题I would never have _______Jim of committing the theft.

单项选择题John, how lazy you are! This work _____three days ago.

单项选择题_______I got home______ that I had the wrong umbrella.

单项选择题The library _____, so it won't be available for students.

单项选择题One of the fifty states in the United States___ an island, Hawaii.

单项选择题The word processor _______of a keyboard, a monitor and a printer.

单项选择题______has been done to stop pollution caused by traffic.

单项选择题What do we learn from the conversation

单项选择题What do we know about Mark from the conversation