简要分析我国古代对外贸易的特点以及对我国社会经济发展的影响。
What is the main reason for using the "ip ips deny-action ips-interface" IOS command？（） [" To selectively apply drop actions to specific interfaces"," To enable IOS to droptraffic for signatures configured with the Drop action"," To support load-balancing configurations in which traffic can arrive via multipleinterfaces "," This is nota valid IOS command"]
1850 TSS通用矩阵可以进行以下业务的交换（） ["波长业务","数据包业务","TDM业务"]
服务礼仪主要是以服务人员的仪表规范、（）、语言规范和岗位规范为其基本内容的。 ["站姿规范","坐姿规范","走姿规范","仪态规范"]
《学生体质健康标准》的评价指标规定，大学各年级的评价指标有5项：身高标准体重、肺活量体重指数为必评指标；某大学女生还可选择（）作为选评指标。 ["800米跑、仰卧起坐、立定跳远","800米跑、台阶试验、立定跳远","800米跑、仰卧起坐、50米跑","800米跑、引体向上、坐位体前屈"]
吊车钢丝绳的使用和保养内容有什么？
