The president was so absorbed in his work that not a sound ______.
–You’re not worried about your English, are you? --No, certainly not. Not Chinese, not math and _____ English.
If it were not for the fact that she _____ sing, I would invite her to the party.
You see the lightning _____ it happens, but you hear the thunder later.
She had no idea how it _____ that her husband met with trouble again.
As far as I’m concerned, education is about learning and the more you learn, ______.