#1 seems OK to me. #2 is wrong.The answer is 1, but I don't like the word "dissociated". Is it common? Also 2 seems to make same, but it sounds unnatural. What do you think?
35)Which can replace the underlined?
Humans who lived as hunter-gatherers more than 10,000 years ago fitted into ecosystems by acting as predators, and on occasion they
probably also served as prey. The role of humans in today’s ecosystems differs from that of early human settlements. Today, humans in almost every part of the world no longer interact with nature as they once did. People have detached themselves from most ecosystems. Modern humans also tend to negatively affect ecosystems in ways that the earliest civilizations did not. One aspect of the study ofecosystems in environmental science provides a clue as to how disconnected humans have become from nature. Many ecosystems are named for the dominant species within them.Therefore, the world contains coral reef ecosystems, evergreen forest ecosystems, grassland ecosystems, and so on, but environmental science contains no “human ecosystems."
1.how dissociated human beings have become from nature
2.how disconnected nature has become from civilizations.
Student or Learner