I only see 3 excerpts.....those I can see would be as follows:
1) Society and class
2) humankind and nature
3) evolution
Don't know why the other 2 excerpts don't show up (for me)
There are several ways in which scientists attempt to eliminate mistakes and fake results from their research. For example, the use of the scientific method allows scientists to experiment (in most cases), which allows them to see whether their results can be replicated in real life.
Another method is through peer-reviewing systems for scholarly review. This means that scientists check each other's work to make sure it meets some quality standards. Also, it is a way to stop incomplete or erroneous information from spreading.
Its linking 2 closely related independent clauses.
You should put a screen shot and we can help you
