How are you doing(等于这里的how he was doing）是问候语,比较口语,类似于what's up,译为：你最近怎样?说话的人不仅认识,还比较熟.If I were any better,I would be twins
意译 如果我能够更好一点点,我就成双胞胎了!
直译 我再好不过了.等于I'm doing good/I'm doing ok