合作。
When BGP tuning is used， how is packet flow into the e-commerce module controlled？（） ["by tracking the status of objects along the path to the e-commerce module","by detecting undesirable conditions along the path to the e-commerce module","by using the MED to communicate the site preferences for traffic to multiple ISPs","by communicating the available prefixes， routing policies， and preferences of each site to its ISP","by moving the SLB to a position where selected traffic to and from the servers does not go through the SLB"]
原生动物
放线时，越线架与公路的最小垂直距离为（）m。 ["4","5","5.5","6"]
企业按应收账款余额的5%计提坏账准备。2007年初，“坏账准备”账户期初余额为2万元，当年末应收账款余额为100万元；2008年确认坏账损失3万元，收回以前年度已注销的坏账1万元。2008年末应收账款余额为80万元，则当年末应计提坏账准备（）。 ["4万元","2万元","1万元","0"]
简述商品质量监督的作用。
