减值损失会在利润表中确认loss，会影响税前利润，同时也会减少当年的税款。并不明白题目解析中，所说只有当损失被实现的时候，应付税款才会被改变。这句话的意思，能否给解释一下
问题如下图：
选项：
A. 
B. 
C. 
解释：
NO.PZ2016012102000192 问题如下 If a firm recognizeimpairment of its long-livepreciable asset in this year, whiof the following statement woulleast appropriate? A.The recognition woulcrease the pretincome in this year. B.The recognition woulnot change the tpayable in this year. C.The recognition woulincrease the COGS in this year. C is correct.Impairment charges shoulrecognizea loss before trather thincrease of COGS---item woulrecgnizein the inventory writewn.The taxpayable woulonly changewhen the loss wrealize考点 资产减值，treporting financireporting当期发生的资产减值应确认为税前的损失,影响税前利润(pretincome)。资产减值，与存货减值不同，不会增加销售成本(COGS) 应纳税所得额计算中，只有考虑实际已经发生的损失。（资产减值只在资产出售时，才会被税务局确认为损失，影响当期应纳税所得额） 长期资产impairment loss不影响COGS；那么影响损益表中的什么？
NO.PZ2016012102000192问题如下 If a firm recognizeimpairment of its long-livepreciable asset in this year, whiof the following statement woulleast appropriate?A.The recognition woulcrease the pretincome in this year.B.The recognition woulnot change the tpayable in this year.C.The recognition woulincrease the COGS in this year. C is correct.Impairment charges shoulrecognizea loss before trather thincrease of COGS---item woulrecgnizein the inventory writewn.The taxpayable woulonly changewhen the loss wrealize考点 资产减值，treporting financireporting当期发生的资产减值应确认为税前的损失,影响税前利润(pretincome)。资产减值，与存货减值不同，不会增加销售成本(COGS) 应纳税所得额计算中，只有考虑实际已经发生的损失。（资产减值只在资产出售时，才会被税务局确认为损失，影响当期应纳税所得额） 为什么税前收入都减少了，应付税额却不变
NO.PZ2016012102000192问题如下If a firm recognizeimpairment of its long-livepreciable asset in this year, whiof the following statement woulleast appropriate?A.The recognition woulcrease the pretincome in this year.B.The recognition woulnot change the tpayable in this year.C.The recognition woulincrease the COGS in this year. C is correct.Impairment charges shoulrecognizea loss before trather thincrease of COGS---item woulrecgnizein the inventory writewn.The taxpayable woulonly changewhen the loss wrealize考点 资产减值，treporting financireporting当期发生的资产减值应确认为税前的损失,影响税前利润(pretincome)。资产减值，与存货减值不同，不会增加销售成本(COGS) 应纳税所得额计算中，只有考虑实际已经发生的损失。（资产减值只在资产出售时，才会被税务局确认为损失，影响当期应纳税所得额） 存货减值损失会影响COGS？中国的准则是不是不影响COGS，因为分录是 借 资产减值损失 贷存货跌价准备
NO.PZ2016012102000192 The recognition woulnot change the tpayable in this year. The recognition woulincrease the COGS in this year. C is correct. Impairment charges shoulrecognizea loss before trather thincrease of COGS---item woulrecgnizein the inventory writewn. The taxpayable woulonly changewhen the loss wrealize 考点 资产减值，treporting & financireporting 当期发生的资产减值应确认为税前的损失,影响税前利润(pretincome)。资产减值，与存货减值不同，不会增加销售成本(COGS) 应纳税所得额计算中，只有考虑实际已经发生的损失。（资产减值只在资产出售时，才会被税务局确认为损失，影响当期应纳税所得额） 摊销是在I/S表中记提一个preciation，减值是在I/S中记提一个LOSS。摊销和减值都不影响实际税额。只有把资产卖掉时，账面损失差额记在COGS中。学的有些懵，上面理解的有问题吗？请老师帮忙横向对比下
NO.PZ2016012102000192 The recognition woulnot change the tpayable in this year. The recognition woulincrease the COGS in this year. C is correct. Impairment charges shoulrecognizea loss before trather thincrease of COGS---item woulrecgnizein the inventory writewn. The taxpayable woulonly changewhen the loss wrealize 考点impairment，treporting & financireporting pretax是financiaccounting的数字，减值必然会使pretincome减少，A正确。 但是税务局不认企业的减值，税务局计算taxable income的时候是要把减值的影响因素剔除的，所以tpayable的计算结果不受到减值的影响，B也正确。 与存货减值不同，长期资产impairment loss不影响COGS，C说法不正确。因此本题选我理解减值会导致折旧减少，折旧减少不是会导致tax降低吗，但是对pretax的影响是如何推导出来的呢？
