A flashing red light displayed at a single lock means that the lock（）. is ready to use but vessels must stand clear。 is ready to use and vessels may approach。 cannot be made ready immediately and vessels shall stand clear。 cannot be made ready immediately but vessels may approach。
海船规范规定逆功率保护延时动作的时间为（）。 3s以下。 3s～10s。 15s。 30。
A flashing green light displayed at a single lock means that the lock is（）. ready for entrance。 ready for entrance，but gates cannot be closed completely。 being made ready for entrance。 not ready for entrance。
船舶报警系统手动检测应每月进行一次。
船舶水灭火系统应每半年进行一次全面检查。
在动物细胞培养过程中要用什么显微镜来观察细胞分裂状况？（）
