1. 图一 effective tax rate = marginal tax rate 您能先给我讲下这两个名次的概念么？ 然后这里有公式可表明他们等么？如何退出来的这个结论？2. repurchase 对EPS 影响为什么是uncertain ？3. stock div 对ownership value 为什么是no changes 是因为等比例么？4. 图二 stock spilit 对financial ratio无影响？这financial ratio 指所有ratio 么？

1. 图一 两个打问号，rd小于Re？ 另一句话意思是说这样rd 就会变小么？2. 图二 上半部分股利无关论，您能给我举个例子说说么？下半部分 打问号两句话如何理解？3. 图三 打问号这句话如何理解？

1. 图一 最底下画❓句子如何理解？ 2. 图二 最后一句话 说通胀对all rev 和 cost 无影响？ 3. 图三 这3个打问号的 分别如何理解？

8 A cyclical company is most likely to:A have low operating leverage.B sell relatively inexpensive products.C experience wider-than-average flutuations in demand.老师，这一题A为啥错？原版书找到这段话，”Such companies experience wider-than-average fluctuations in demand—high demand during periods of economic expansion and low demand during periods of economic contraction—and/or are subject to greater-than-average profit variability related to high operating leverage (i.e., high fixed costs).“，这里的意思是说周期性公司具有高经营杠杆吗？

6 Which of the following statements about commercial and government industry classification systems ismost accurate?A Many commercial classification systems include private for-profit companies.B Both commercial and government classification systems exclude not for-profit companiesC Commercial classification systems are generally updated more frequently than government classification systems老师，1. 原版书哪里有提到商业行业分类体系只包含公开上市、营利性企业？2. 商业和政府行业分类体系的对比有哪几点老师可以列一下吗？

reading13第13题，with the right to pay-fixed on a 30-year swap, which increases in value if long-term yields rise.这里增值是说swaption吗？为什么长期利率涨payerswaption增值？因为锁定了payerleg？

请问r26课后题第12题，如果是主观题的话，只算selection effect，而不是selection+interaction，行不行？我看答案解析用的是selection+interaction

rea;ding13课后题9这里B为什么会有negativecarry

为什么这里求谁的离散程度更大？是选A：1%而不是B：8%？明明8%更大

positivebutterfly为什么是指spread变窄？这里我应该怎么理解？按理说positive的话按字面不是应该保持或者spread加宽吗？这里说positive感觉反倒是和字面意思反过来？