Everyone knows that _______ is dangerous to play with fire, but _______ is difficult is to prevent children from playing with fire.
In Scandinavian countries it is common ____ for the husband to stay at home to look after the baby.
He has ____ letters to deal with. He has to work from morning to night.
Social attention should be paid ____ our earth from ____.
–It’s hard for me to go to sleep. –Try to ____ the amount of coffee you drink during the day.
There was a big fire in the building last night. ____, all the people were able to escape.