美国医疗体系中“保险控制医疗”是指（）。 ["全额担保","部分担保","医生的处方要遵循保险公司意见","保险公司的优惠政策"]
体循环中，当血液流经下列哪类血管时，流速降幅最大：（） ["大动脉","微动脉","毛细血管","微静脉"]
用电弧焊焊接较厚的工件时都需开坡口，其目的是（） ["保证根部焊透","减少焊接应力","减少焊接变形","提高焊缝强度"]
A long pole with a hook at one end，used to reach for lines，is known as a（）. ["pike pole","jack staff","line rod","hooker"]
塔式起重机的结构件，多采用（） ["钎焊","埋弧自动焊","手弧焊","电渣焊"]
简述中国古代的战争观。
