A．should have done B．must have been doneC．should have b……

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

单项选择题What can we learn from the conversation

单项选择题What is Susan's trouble now