单项选择题
When a vessel is passing through a narrow channel, it s...
单项选择题When a vessel is passing through a narrow channel, it should________. A、keep far away from the outer limit B、keep as near to the outer limit as possible C、sail as slowly as possible D、sail as quickly as possible
药品的容器应无毒、洁净,内容物与容器不应发生化学变化。
判断题药品的容器应无毒、洁净,内容物与容器不应发生化学变化。
为了防止因气门弹簧共振而破坏配气正时,通常安装( )。 A. 双气门弹...
多项选择题为了防止因气门弹簧共振而破坏配气正时,通常安装( )。 A. 双气门弹簧 B. 变螺距气门弹簧 C. 锥形气门弹簧 D. 气门弹簧振动阻尼器