[单选] As soon as the ship is berthed，you should lower the gangway，stretch a net（）it，and adjust it to the rise and fall of the tides so that personnel may embark or disembark in safety．

战勤保障大队空气呼吸器备用气瓶储备数量为200只。 战勤保障大队正压式空气呼吸器储备数量为30具。 从底层支撑技术层面看，整车控制系统的组成部分是什么？ 永磁电机主要存在哪些问题？ 战勤保障大队方位灯储备数量为50只。 As soon as the ship is berthed，you should lower the gangway，stretch a net（）it，and adjust it to the rise and fall of the tides so that personnel may embark or disembark in safety．