The company had about 20 notebook computers but only one-third __________ usedregularly. Now we have 60 working all day long.
They eat less sugar and that’s ______ they have ______ white teeth.
--- Do you know the big news that Joan will marry Frank soon?--- Marry Frank? _________ She told me she would keep single.
Not a single book is allowed _________ out of the reading room according to the new rule.
The professor said that he was interested only in research; he didn’t ________ others’ comments.
To my parents’ relief, both my brother and I followed the family _____ and became doctors.