p167Task2 The words in bold are from Listening Skills& Strategies in this part. Listen to their explanations. Then complete each sentence with the correct word. You may change the form when necessary.A.A galaxy is a large system of stars held together by mutual gravitation and isolated from similar systems by vast regions of spaceB. If something is crystal-clear, it is absolutely clear and clean.C. Plague as a verb means to cause worry, pain, or trouble to someone, especially for a long period of time.D. Distort means to change the appearance, sound, or shape of something so that it is strange or unclear.E. An orbit is the curved path traveled by an object which is moving around a much larger object such as the Sun, the Earth, etc.1. Water shortages are a problem many large cities in this country.2. First of all the clues were not collected just after the murder and we have a feeling that everything was done the investigation and to lead it in a certain way.3. Today we know it is gravity that holds the planets and stars in theirmaking them appear to be hung on nothing4. Most telepresence systems are two-dimensional. “It's a 2-Dimage, but it's , photo realistic, fluid movement, accurate flesh tones, and you would swear you were in the same physical space with people who might be thousands of miles away.”5. Black holes are known to devour matter but did they arise before or after thein which they exist?[音频]