阅读理解。 We often see planes speed up on the runway and take off at the airport. Can this happen on the water? Aircraft carriers (航空母舰) make it possible. An aircraft carrier is a type of ship that planes can fly from-and land on-like an airport on the sea. On the foggy mo/'ning of August 10, China's first aircraft carrier began its trial run at Dalian Port in Liaoning and returned four days later. The carrier was at first called the Varyag ('瓦格良'号). It was built in the former Sovriet Union (前苏联). However, the Soviets failed to complete the ship. China bought the Varyag in 1998 from Ukraine (乌克兰) after the former Soviet Union collapsed (解体). After the first sea trial, China will go on refitting (改装) the ship and doing test work. Building an aircraft carrier is hard work. There is still a lot to do, such as training pilots. Many people remember the aircraft carriers of World War II, a war in which big ships played an important role. The Japanese attacked the US Navy at Pearl Harbor (珍珠港) in 1941 by surprise with the help of an aircraft carrier. The Japanese also lost the Battle of Midway (中途岛之战) with the US in 1942 because their carriers were hit. Only nine other countries in the world have aircraft carriers. Some countries consider a Chinese aircraft carrier a threat. But China's Defense Ministry (国防部) spokesman Geng Yansheng said: 'China always sticks to the road of peaceful development. The aircraft carrier is for protecting national security (安全) and doing more for world peace.' 1. The underlined phrase 'trial run' means  _____ in Chinese. A. 试飞 B. 试航 C. 实施 D. 实验 2. After the first sea trial, China will _______. a. refit the ship again b. do a lot of test work c. sell this aircraft carrier d. train some pilots A. abc B. bcd C. abd D. acd 3. The fifth paragraph mainly tells us about _____ of aircraft carriers. A. the threat B. the history C. the disadvantages D. the importance 4. _____ countries in the world have aircraft carriers. A. Ten. B. Nine. C. Six. D. Four. 5. We can tell from the story that ______. A. China's first aircraft carrier was built in Ukraine B. it took six days for the carrier to finish its first trial C. China will use the carrier to protect national security D. a Chinese aircraft carrier is welcome all over the world