单选题 7. Replace filter element/worn parts

单选题 2. Conduct routine maintenance

单选题 1. Perform pre-flight/post-flight inspection

单选题 4. Top up hydraulic/fuel/oil fluid

单选题 8. Inspect for cracks/leaks/wear

单选题 3. Check fluid level/pressure

单选题 5. Torque bolts to specification

单选题 6. Clean air/fuel/oil filter