定子水系统的电加热器有什么作用？
变速器壳的底部贮存的工作油是供（）等系统所用。 液力变矩器。 变速箱操纵阀。 散热器。 液力换档离合器。
某工地招标文件规定，"招标人应出具10万元的银行保函或等额汇票作为投标担保"，则该工程担保的方式包括（） 保证。 抵押。 动产质押。 权利质押。 定金。
根据施工劳务分包合同示范文本的规定，可以调整劳务报酬的情况是（）。 由于劳务分包人原因造成的返工。 通货膨胀导致劳务价格变化。 法律政策变化导致劳务价格变化。 由于劳务分包人原因造成的安全事故。
Refer to the exhibit. What is the sequence of events when a VoIP call is placed from IP phone P1 to IP phone P2？ （） RTP traffic is exchanged between IP phone P1 and IP phone P2. IP phone P1 alerts the CCM of off-hook state. CCM instructs IP phone P1 to provide dialtone. IP phone P1 passes digits to CCM. CCM routes call to PSTN or IP phone P2.。 CCM instructs IP phone P1 to provide dialtone. IP phone P1 alerts the CCM of off-hook state. IP phone P1 passes digits to CCM. CCM routes call to PSTN or IP phone P2. RTP traffic is exchanged between IP phone P1 and IP phone P2. 。 CCM instructs IP phone P1 to provide dialtone.IP phone P1 alerts the CCM of off-hook state. IP phone P1 passes digits to CCM. RTP traffic is exchanged between IP phone P1 and IP phone P2. CCM routes call to PSTN or IP phone P2.。 IP phone P1 alerts the CCM of off-hook state. CCM instructs IP phone P1 to provide dialtone. IP phone P1 passes digits to CCM. CCM routes call to PSTN or IP phone P2. RTP traffic is exchanged between IP phone P1 and IP phone P2.。
外汇交易的参与者包括（）。
