The current economic downturn has significantly reduced advertising income both for business journals as well as general consumer magazines, especially if focusing on technology.

1. has significantly reduced advertising income both for business journals as well as general consumer magazines, especially if focusing

2. has significantly reduced advertising income both for business journals and for general consumer magazines, especially those focusing

3. significantly reduced advertising income for both business journals and for general consumer magazines, especially when focused

4. reduced both business journals’ and general consumer magazines’ advertising income significantly, especially if focused

5. reduced advertising income significantly for both business journals, as well as for general consumer magazines, especially those focusing

请问这里的those focusing是什么结构呢?

D有什么错误呢?

答案是B,请指教,先谢谢了!

D，especially when focused没有主语，如果是时间状语从句的话，那主语就变成了The current economic downturn 。则逻辑意思不正确。应该是business journals 和general consumer magazines focus才对

B，those指代business journals 和general consumer magazines，focusing是分词做定语修饰those，因为前面是逗号，不用－ed形式，用－ing形式表主动