It is said that bad living habits as well as dirty surroundings, stuffy rooms and some other factors _____ the wide spread of H1N1.
_______ the fact that three quarters of the earth’s surface is covered with water, we can say that it is a ________ planet.
It _______ that I had forgotten to lock the door this morning before I left home.Which one of the following answers is NOT suitable? ________
At the back of the book _______ of the works available for further research.
Without the air to hold some of the sun’s heat, the earth at night _____ too cold for us to live.
It sounds like a good idea, but it _________ to be seen whether it will succeed.