Thanks for the comments, wunaide.
I know that not all people write perfectly. But as it's in my textbook as reading material, I didn't think it was an erroneous type of writing.
The editor of my text is a Japanese, so he/she might have thought like "OK, this writing is kind of complicated. So let's use this stuff for the advanced."
Speaking of coherency and meaningfulness, could you please help me out of this problem?
It's from the same writing, and I'm in deep trouble understanding it. But you've made me realize that it might not be anything about grammar, but about his/her sloppy writing style.
I'm looking forward to your comments.
(P.S Is English your frist language?)