They both have________homework to do,so they may be________busy doing it now.
I saw himwhen I passed by.
Bob used to ________in the countryside . But now he is used to _________in the big city .
---You’d better not eat too much salt. It's bad for your health. ---- _______________.
Yesterday, they talked about something important _______ the phone.
His father told him ________ his best friend to dinner this Sunday.