Although______expenses works well when applying for a contract,
clients appreciate itemization on their invoices.
(A) estimate (B)estimator (C)estimating (D)estimation
答案是C
我第二次复习, 还是错在这题
Although+S+V, 所以我一直不太确定是省略S, 加Ving 吗？
先谢谢大家

跟后面的主词一样所以省略 动词改ving保留

although是连接词主词: estimating expenses动词: workswhen可当连接词也可当介系词，这里当介系词，后面接名词: "applying for a contract"另一个主词: clients另一个动词: appreciate

https://pttweb.tw/toeic/m-1484157199-a-f3f.html对照这一题 https://goo.gl/mtCneR