我选A。原因1. industries that are more established没有the more established industries简洁。2,其实A和B的主要不同在后半句:A是companies that compete one day may be partners the next.B是competing companies one day may be partners the next.这个B有没有one day都别扭。3,原文优先:)
我選A 以下是我的意見 1.they 在AB兩句都沒有廣泛指代的問題,因為語法規則說代名詞優先代替原題主詞,這兩句的主詞均為lines 所以they沒有問題 第一句還原應該是 Whereas lines of competition are clearly defined as companies that compete one day may be partners the next in the more established industries, they are blurred and indistinct in the internet industry. 但是語法規則說 不可以頭重腳輕~這面這句頭很重 腳很輕 2. 第二句錯誤主要是改變了原題的句意 as competing companies跟 as companies that compete 句子意思完全不同 美國人會跟你老生常談這akward.... 所以一切都是 懂得句意為先