According to the principle of operation, navigation system can be divided into instrument navigation systems, , inertial navigation systems, astronomical navigation systems and integrated navigation system.
【简答题】Section B Directions: Inthis section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once, After you h...
【简答题】16-19.mp3: Section B Directions: In this section, you will hear 3 short passages. At the end of each passage, you will hear some questions. Both the passage and the questions will be spoken only once....
【简答题】CET4-LISTENING-SECTIONB.mp3: Section B Directions: Inthis section, you will hear 3 short passages. At the end of each passage, youwill hear some questions. Both the passage and the questions will be s...