The world today is faced the questions or threats. The most dangerous threat of all is war, and after the threat of war is (1) ________. People all over the world worried about things that are happening to the environment. Actually, it is man that is destroying the surrounding with (2) ________ kinds of wastes from the devices that make human lives more comfortable and convenient. Everybody knows that motorbikes and cars emit dangerous gases (3) _______ cause poisonous air and cancer, but no one wants to travel on foot or (4) _________ bicycle. Manufactures know that wastes from factories make water and soil polluted, but they do not want to spend a lot of their money on (5) _______ the wastes safely. Scattering rubbish is bad for our health, but no one wants to spend time burying it. Is it worth talking a lot about pollution?

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of  the question.

The most dangerous threat of all is war, and after the threat of war is (1) ________.