__________ puzzles me most is that I don't know __________ the difference between the two lies.
It is time for class to start. The teacher __________ be in the classroom now.A. can B. should C would D. shall
The opening day of Expo 2010 Shanghai China we have been forward looking to_____ to arrive.
_________the peace talk between the two countries will break down depends on your attitude.
It was __________ you had done ________made it possible for you to improve your English.
—May I use your computer?—Sure, _____________