老师好，课堂讲long call是增加convexity，这个我明白。那long put short call short put，原因呢？

你好，老师。原版书课后有一道题： Zimt AG uses the FIFO method, and Nutmeg Inc. uses the LIFO method. Compared to the cost of replacing the inventory, during periods of rising prices, the cost of sales reported by:(A) A. Zimt is too low. 答案解释中有一句话：Nutmeg uses the LIFO method, so its cost of sales is approximately equal to the current replacement cost of inventory.

你好，老师。想问的是：inventory cost指的是可以被Caitalized的那部分，而inventory expense指的是能够被Expensed的那部分？

你好，老师。原版书课后习题中有一道题：Inventory Cost is least likely to include(C) C. transportation costs of shipping inventory to customers. 答案中解释到： Transportation costs incurred to ship inventory to customers are an expense and may not be capitalized in inventory.(Transportation costs incurred to bring inventory to the business location can be capitalized in inventory) 不太理解这里的运输成本是需要分情况考虑吗？将存货运输给客户可能不被资本化，而将存货运输到交易地点才能被资本化，我这样理解的正确吗？

请解答下13题

关于正态分布没有太明白，X~N(0,1)和X~N(1,4)的图形差异是如图所示吗？那方差分别是1和4，在图形上是怎么表现1和4的差异的？

22题请讲解

组合题目的18-19请讲解

老师您好，截图是notes原话。有不明白的地方，1这个策略讲课里没讲。2讲课里讲的call option是assume duration为0。如何来理解？

问题一: 如图; 问题二: 以call为例, 第一个圆圈中的value of an embedded call option是指嵌入式的; 那第二个圆圈中的value of a call option是指独立的call option? 分别回答, 谢谢