-----They used to be good friends, but now they are like strangers. ----- How _____ this ______?
He found that complex problems, especially those _____ abstract thinking, were best for picking out bright and dull students.
. Don’t promise anything _____ you are one hundred percent sure.
You _____ tell him. He is fully aware of the danger.
_____ his ability of speech, he has made use of each chance.
People pay ______as to the content of your speech.