1. [单选题]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
2. [单选题]向侧立投影面(W)上投射得到的视图，称为( )。
A. 主视图
B. 左视图
C. 俯视图(top view)
D. 仰视图
3. [单选题]下列关于对了员的要求说法正确的有：I、了望人员应具有健康的身体素质，尤其是能适应视觉和听觉了望的基本要求；II、不能船上人员的多少，了望人员只能由合格的、称职的航海人员来担任；III、只要具有健康的身体素质，能适应视觉和听觉的基本要求的船员均可作为了望人员
A. I
B. I、III
C. I、II
D. I、II、III
