单项选择题 Main steam and exhaust pipes for winches and similar gear shall not pass through crew accommodation nor, whenever technically possible, through alleyways leading to crew accommodation; where they do pass through such alleyways, they shall be adequately （）.

单项选择题 A solenoid valve used in a refrigeration system should be installed （）.

单项选择题 When a refrigeration compressor is in the ‘off’ cycle, the thermal expansion valve will（）.