----Hi, John. Are you still a smoker? ---- . It’s two years since I stopped smoking.
I tried phoning her office, but I couldn't __________.
I don't think these issues are __________ discussing with the ministers.
The rise of oil prices made scientists search for new energy re-sources to __________ oil.
The parents couldn't tolerate __________ the messy __________ in the room.
The speed of cars is usually limited __________30 miles per hour on the busy city street.