Prof. Richard was crazy about his research. His illness_________ his many years of hard work and irregular diet.
— ____ I go out to play now , Mum ? — No , you ____ .
Help me with this suitcase , ____ you ?
Why ____ you keep on troubling me with such questions while I''m busy ?
____ tennis every day ?
I saw him leave the office an hour ago . He ____ at this time .