Tsunami is a natural disaster, which is a Japanese word that means "sea wave". A tsunami is a huge sea wave that forms mainly in the Pacific Ocean area. People die and property is destroyed when a tsunami hits land. What causes these dangerous sea waves? Sometimes, tsunamis are caused when earthquakes take place underwater. Then, water begins to move up and down from the top of the ocean right down to the bottom. Waves begin to form, and each wave is called a tsunami. A tsunami is less than one meter high and can move at a speed of almost 800 kilometers per hour while it is far out in the ocean. But the tsunami rises much higher and moves more slowly as it comes closer to land. The weather bureau warns people over the radio and television when a tsunami is heading for land. These warnings have helped save many lives. According to this passage,   _  .
a tsunami can't cause lots of trouble people can save their lives when a tsunami is coming the warning from the weather bureau can help people save their lives no one can escape when a tsunami is coming