Make sure the work area is clean and clear of tools and other items and all access panels are closed.

A. You can calibrate all the compass systems at the same time.

B. You can fix all the compass systems at the same time.

C. You can calibrate all the magnetic needle systems at the same time.

A. If abbreviations have special meanings, they may be used.

B. Abbreviations should not be used if they are universally meaningful.

C. Only use abbreviations whose meanings are generally recognized.

A. The units and components which store, regulate, and deliver oxygen to the passengers and crew include oxygen bottles, relief valves, shut-off valves, outlets, regulators, masks, etc.

B. The units and components which reserve, adjust, and transfer oxygen to the passengers and pilots include oxygen bottles, relief valves, shut-off valves, outlets, regulators, masks, etc.

C. The units and components to store, adjust, and transfer oxygen to the passengers and crew include oxygen bottles, release valves, shut-off valves, outlets, regulators, masks, etc.

A. The following synonyms are used interchangeably throughout this section and they are the sample of one system and device respectively.

B. The following antonyms are used interchangeably throughout this section and they present the same system and device partly.

C. The following acronyms are used interchangeably throughout this section and they represent the same system and device respectively.

A. 发动机除冰系统用来消除和杜绝引气在发动机所有部件中形成冰，不包括第30章所述的动力装置整流罩。

B. 发动机防冰系统通过引气来消除和防止发动机所有部件结冰，不包括第30章所述的动力装置整流罩。

C. 发动机防冰系统用于减缓和防止引气在发动机所有部件中形成冰，包括第30章所述的动力装置整流罩。

A. Normally, it is named “fly by electrical control system”.

B. Normally, we name it “fly by electrical system”.

C. This is commonly referred to as “the flight by wire system”.

A. Advisory circular must always be carried out on aircraft.

B. Advisory circular is the procedure that must be used when performing maintenance on an aircraft.

C. FAA provides advisory circular which is not always carried out on aircraft.

A. Warning is an operating procedure, inspection , repair or maintenance practice , which if not correctly followed, could result in personal injury , or loss of life.

B. You should obey the warning in an operation procedure, check, repair or maintenance practice, otherwise person injury or death will happen.

C. Warning in an operation procedure, inspection , repair or maintenance practice should be followed seriously, whereas may involve in personal injury , or loss of life .

A. It supersedes the preceding edition.

B. It updates the previous version.

C. It takes place of the following version.

A. 机翼和发动机载荷取决于最大起飞重量和额定起飞马力以及机翼面积。

B. 机翼和电源负载取决于最大起飞重量和起飞马力评定值以及机翼面积。

C. 机翼和动力载荷决定了最大起飞重量和起飞马力评定值以及受力表面积。