It's OK to________an electrical appliance on so long as you are using it.
______ different life today is from ______ it was fifty years ago.
The driver was at ______ loss when ______ word came that he was forbidden to drive for speeding.
You can take the rest of the pie with you. ________, I wish you would, since I’m on a diet.
With the word “ PM2.5” ________ appearing in media reports, people pay greater attention to it and seek health tips for smoggy days.
He is talking so much about America as if he _____ there.