When a marine surveyor is employed to assist in the move of a mobile offshore drilling unit，he（）. ["becomes responsible for the safe movement of the rig","relieves the Offshore Installation Manager at the moment the rig is free from the bottom","must be designated as the person in charge of the rig","is a specialist who is hired to provide advice and guidance on aspects of the move"]
飞行中出现危险品事故着陆后，以下哪项措施是错误的？（） ["地面人员打开货舱门之前应让旅客下飞机","打开货舱门之前应让机组下飞机","打开货舱门之前旅客和机组保留在飞机上","向地面工作人员指明危险物品及其存放地点"]
适度放牧的草场在不放牧之后将发生的现象是：（） ["植物竞争强度增加","植物竞争强度降低","植物种类增加","植物种类减少"]
某公司作为新兴企业，在发展阶段选择了类似于市场主导企业的渠道成员作为自身渠道伙伴，然而经过竞争，公司管理者决定另辟蹊径，通过刺激消费者拉动终端渠道与之合作。整个过程中该公司选择了（）。 ["分阶段选择策略","参照选择策略","开拓选择策略","逆向拉动选择策略","推动选择策略"]
影响九寨沟植物垂直分布的主要非生物因素是：（） ["大气","温度","水分","阳光"]
简述茎双穴吸虫病的病原。
