Many people believe we are heading for environment disaster we basically change the way we live.
A. if B. but C. unless D. once
Many people believe we are heading for environment disaster we basically change the way we live.
A. if B. but C. unless D. once
C
考查连词。语意：很多人认为我们很可能遭受环境危机，除非我们从根本上来改变生活方式。据此用unless“除非”符合语境，答案选C项。