Back in the 1960s and 1970s, the world was becoming more aware of the destructive effects of industry (23)__________the environment and people were starting to think seriously about ways of p
Back in the 1960s and 1970s, the world was becoming more aware of the destructive effects of industry (23)__________the environment and people were starting to think seriously about ways of protecting the environment.
A. for
B. to
C. with
D. on