幼儿园常见的主题类型有：围绕（）开展的主题；围绕自然环境开展的主题；围绕社会环境与生活开展的主题；围绕人类与科学技术开展主题；围绕重大事件开展主题。
20世纪末期的美国联邦税收显示，曾经支付了占联邦税收总数30%的公司，现在只贡献了12%。导致这一现象的原因是（）。 ["经济全球化的加剧","政治多极化的加强","凯恩斯主义的盛行","新自由主义的崛起"]
种群的空间结构。
网箱设置怎么选择？
What best describes processing delay？（） ["the time required from receipt of the incoming frame， until the frame\/packet has been queued for transmission","the time taken for a single packet to traverse the physical medium from one end to the other","the time taken to place a frame on the physical medium for transport","the time spent for a packet to reside in the output queue of a router"]
客运架空索道按其运行方式分为哪几类？
