Why were some people critical of britain's imperialist practices?

I believe the answer is: Because colonizing often involved

In the past, in order to obtain cheaper workers and resources, Britain imperialist tend to colonoize a weaker country and force them to follow an agreement that provided the imperialist with what they want. Because of this, many people are critical on how they accumulate their wealth.

gay mainly is used with men and homosexual can be used with men and women

i believe it is the first choice (1.)

because the major theme is(“both the wild and civilization have rules.”)

and also as u said,( based on what buck learns within the call of the wild, "both the wild and civilization have rules".this is true of humans within society as well.