1218、Solenoid valves shall be shown with a notation indicating whether the valve is spring-loaded to the open or closedposition.

271、Airworthiness Directive is procedure that must be used when performing maintenance on an aircraft

270、The system interface circuits adapt to the physical properties of the connected systems.

269、In a high concentration, this material is poisonous.

268、The flight crew can use the flight director commands to control the attitude of the airplane.

267、Do test B as an alternative to test A. 做测试 B 作为测试 A 的替代方案。

266、Care must be taken not to damage the firewall cover.

265、The topic sentence is the first and most important sentence in a paragraph.

264、The laptop has three primary parts.

263、The writing rules cover aspects of grammar and style. The dictionary gives the general words that awriter can use.

262、This method is recommended as minimizing errors of distribution, and also informs owners of theavailability of systems and equipment.