Mr. Keller ______ forty cigarettes a day until he gave it up.
Tom ________ in the library every night over the last three months.
Reading is ________ good habit. Stick to it, and you’ll make ________great progress.
-----May I ask a question after class, Sir? -----_______, but not during my lunch break.
We went through a period _______ communications were very difficult in the rural area.
A person ______e _mile account is full won’t be able to send or receive any e _mails.