It is the prevention of disease_____ its successful treatment that has led to the rapid increase of the world’s population.

-- Do you think it's a good idea to make friends with your students?-- ______, I do. I think it's a great idea.

After many years’ waiting, Chinese people______ realized their dream to hold the Olympic Games.

--This store has such high prices.--- I agree. Never again ___ here.

The computer, ______________ help we human beings have stepped into the information age, should be made full use of to promote the social development.