下列属于国际融资担保的是（）。
A、股票买卖
B、见索即付保证
C、备用信用证
D、浮动抵押
E、意愿书
参考答案：B, C, D, E
I was really anxious about you. You ____ home without a word. [ ]
A. mustn't leave
B. shouldn't have left
C. couldn't have left
D. needn't leave
裂解炉烘炉后要对耐火材料进行检查，如炉体耐火材料已穿透或宽度大于6毫米，横跨段裂缝大于5毫米时必须更换耐火材料。
