单位体积天然土的总质量称为天然土的（）。 ["质量密度","干密度","饱和密度","浮密度"]
作为旅行社和旅游地为旅游者提供的导游服务包括（） ["讲解服务","翻译服务","旅行生活服务","信息资讯服务","劳务服务"]
根据休谟，相信某个东西主要是一种（）。 ["信仰","知识","感觉","直觉"]
导游员向旅游者提供的服务包括（） ["讲解服务","翻译服务","旅行生活服务","信息资讯服务","劳务服务"]
What does Peter do?（） ["He's good at fixing things.","He can speak good German.","He does the washingup after supper","He's a language teacher."]
法规规定谁组织事故调查？
