.I know a little bit about Italy as my wife and I______ there several years ago.

You should thank Peter. It was he who finally ____ your son to stop smoking and playing computer games.

Bad habits are no way easy to be ______; it needs your determination and perseverance.

 In some developed countries, larger population is ______________ in their big cities.

 I had planned to invite Tom to the party to increase the atmosphere, but it turned out that his arrival ____ the atmosphere.