Passage 1 According to the World Health Organization, over a billion adults around the world suffer from high blood pressure. It is now taking steps to fight against what is called a silent killer. High blood pressure can lead to strokes and a heart attack. over = more than billion - million - trillion high blood pressure - hypertension taking steps to - take measures to what is called attack - defend Almost 10 million people die of these two disease every year. They are the number one c ...