In designing schematic diagrams, it may be necessary to compromise between detail necessary to make the diagram self-explanatory and the simplicity essential for ease of reading and understanding.

A. The smoke sensor in each detector monitors when the smoke density is above a previous limit. If the density keeps higher than the limit for about eight seconds, the sensor set the detector to the alarm condition.

B. The smoke sensor in each detector monitors for smoke density above a preset limit. If the density stays above the limit for appropriately eight seconds, the sensor sets the detector to the alarm condition.

C. The smoke transducer monitors for smoke density above a presumed limit of each detector. If the density remains over the limit about eight seconds, the transducer turn the detector to the alarm condition.

A. 如果你不能脱开杆的位置，新杆的长度很可能需要调节。

B. 如果你不能断开杆和活塞，可能量错了新杆的长度。

C. 如果你不能接合杆和活塞，新杆的长度可能是不正确的。

A. 此步骤可以确保燃油泵工作正常。

B. 燃油泵必须要经过这个阶段才能正常工作。

C. 通过这个步骤保证燃料能够到泵的位置。

A. If the filters become clogged, send them to the laboratory for analysis of the contamination.

B. If the filters are surged, send them to laboratory for contamination analysis.

C. If the contaminant is blocking the filter, the material should be sent to the laboratory for analysis.

A. Pilot reports on flight logbook of 908701 pages fluttering sound from left side of airplane during descend beginning at 11000 feet.

B. Pilot reports trembling sound from left side of airplane during ascend at 11000 feet on flight logbook 908701 page.

C. Pilot reports on flight logbook page 908701 fluttering sound from left side of airplane during descend beginning at 11000 feet.

A. You can use the past form of technical verbs as adjectives.

B. You can use the past tense form of technical verbs as adverbs.

C. You can use the past participle of technical verbs as adjectives.

A. After finishing the following procedure, repair the upper flange.

B. Repair the lower flange first during the procedure that follows.

C. Repair the upper flange first during the following procedure.

A. 对现有分析进行了审查，以确定可能表现出较低安全裕度的部件和区域。

B. 对现有分析进行复核，对部件和区域进行标识，以显示出较低安全裕度。

C. 对于安全裕度较低的部件和区域进行标识并进行了现场分析审查。

A. 任何关于限制，仪表标识或者指示牌的改变，会在飞行操作手册的基本限制（第二部分）被说明。

B. 任意改变极限，仪表标记或者指示牌的基本限制应该在飞行员操作手册中规定。

C. 对飞行员操作手册基本限制（第二部分）中的限制、仪表标志或标牌的任何变更均应予以说明。

A. Each of the two life vests located at L2 entry door flight crew station is damaged.

B. Each of the two life vests located at L2 entry door flight crew station is out of time limit.

C. Each of the two life vests located at L2 entry door flight crew station is out of service.