未知题型 The phrase 'once in a blue moon' in last line refers to ______.A.all at onceB.once for a long timeC.once in a whileD.once and for all

未知题型 进出境旅客携带的全部行李物品是指哪个？（）

未知题型 According to the context, the sentence 'But young actors with the stage in their blood are happy' at the end of the first paragraph means ______.A.they don't care if their job is hardB.they like the stage naturallyC.they are born happyD.they are easily satisfied

未知题型 卖家不能够通过下列哪项的综合对比，分析布局商品线？（）

单项选择题 The description is composed by two parts: the overview and _______. A、      questions B、      comparison C、      detailed data D、      contrast