His English is improving _______, which makes both his parents and his teacher happy.
. We should prevent such a silly mistake _____ again.
_____ full preparations, we decided to put off the meeting till next week.
I’m examining the article he has just finished _____ the possible mistakes in it.
Having passed all the tests, she felt a great weight _____ off her mind.
New ideas sometimes have to wait for years before _____.