When replacing a thermostatic expansion valve sensing bulb, it is necessary to
A. apply a light film of oil to increase heat transfer
B. apply a light film of oil to prevent oxidation
C. apply a heavy coating of grease to function as a heat sink
D. carefully coat the device with silicone sealant to reduce the effects of convective cooling
外购成品活塞和配制活塞的尺寸______等均应符合设计图纸的要求。Ⅰ.形状；Ⅱ.配合精度；Ⅲ.位置精度；Ⅳ.热处理要求；Ⅴ.表面粗糙度。
A. Ⅰ＋Ⅱ＋Ⅳ
B. Ⅰ＋Ⅳ＋Ⅴ
C. Ⅰ＋Ⅲ＋Ⅴ
D. Ⅰ＋Ⅳ
With reference to a two-ram actuating mechanism, which one of the following statement is FALSE？
A. The rams work inside cylinders.
B. The cylinders have glands sealing their open ends.
C. The rams are connected to a cross-head
D. The cross-head is mounted on the rudder stock
Indirect cooling of fuel injector nozzle holders for diesel engines is accomplished primarily by
A. heat conduction into the injected fuel oil
B. heat conduction into the water jacket wall
C. water circulation through passages in the holder
D. fuel oil circulation through passages m the holder
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