A computer is so useful a machine ________ we can use everywhere.
We won’t start the work until all the preparations __________.
I think _______ music may clear your mind and reduce pressure.
Hearing this, tears came to my eyes as I realized ________ a fool I had been to judge him to be honest.
— Did you tell Mother you have passed the exam?— Oh, I forgot. I _______ her now.
If he ________ my advice, he wouldn’t have lost his job.