日常社交礼仪
行礼
欧亚大陆桥有（）和（）两条。
What must be carried out in order to launch and inflate an inflatable liferaft? （） ["Pull on the hydrostatic release，pull on the sea painter","Push on the hydrostatic release，pull on the sea painter","Push on the hydrostatic release，push on the sea painter","Pull on the hydrostatic release，push on the sea painter"]
蓝绿藻（菌）和硅藻都以藻命名，其相同处是（） ["都有叶绿体","都有线粒体","都可进行光合作用","都具纤维素细胞壁"]
变压器冷却装置安装前应作哪些检查？如何安装？
