问答题 混凝土在运输过程中，要求混凝土_______、_______、_______、_______、_______。

单项选择题 从商业模式上看，由于B2B交易具有交易量大、订单较为稳定的特点，因此，未来跨境电商交易中B2B仍然是主流。

未知题型 When mentioning 'the something-for-nothing days'(Paragraph l), the writer is talking aboutA.Mr. Blair's unique commitment to public service reforms.B.blank cheques given as a compromise to health workers.C.Mr. Blair's pledge to spending increases on public services.D.pay and conditions granted to health-service workers.

未知题型 以下哪些属于跨境电商企业的物流服务商（）

未知题型 By mentioning 'the figures are as changeable as a mirage in the desert', the author is talking aboutA.the wealthy people who live atop the wells in the GulF..B.the planet's future fossil-fuel supplies.C.the inconsistent estimates on oil deposits in the GulF.D.the oil traded in the international markets.