The book sells well,I guess.为什么这里的I guess要放在后面?

The book sells well,I guess.为什么这里的I guess要放在后面? Well that's something,I guess. I guess it的意思 I guess not 的意思 I guess I do well,I guess I'll have to go to face the 英语翻译well,I guess I showed you.showed me more. the book sells well I guess those are the brakes. 翻译:i guess not IS i guess right? guess who am i