Hydraulic systems are widely used in modern aircraft only in recent years.
举一反三
- ______ is mainly used in light aircraft and only used for emergency on many large aircraft, and its operation medium is ______. A: starting system, oil B: hydraulic system, compressed air C: elevator, hydraulic fluid D: pneumatic system, compressed air
- In recent times, machines are (smart) __________ than they used to be years ago.
- 83. The only cylindrical chart projection widely used for navigation is the _____.
- In<br/>recent times, machines are ______ than they used to be years ago. (smart)
- The use of abbreviation is______ . A: a reflection of modern life in language B: widely used because of the quickened pace of modern life C: commonly used in the United States D: adopted according to the modern way of thinking