Electronic devices such as iPods and headphones can do great harm to our hearing if _______ improperly.
Danby left word with my secretary ________he would call again in the afternoon .
I’m just wondering ___ I first met Tom.
I found her ______ in thought.
The chairman thought _____ necessary to invite Professor Smith to speak at the meeting.
Eating too much fat can______ heart disease and cause high blood pressure.