_____ puzzles me most is that I don’t know ______ the difference between the two lies.
—Can I get you a cup of tea? —________.
David dislikes television heroes who smoke, __________?
— I was hoping you were able to lend me the money. — __________________
It is only with the help of scientific research _____ bring PM1 air pollution under control.
When travelling in America, we stayed in a quiet hotel, __________.