About a century ago, people lived in relative harmony with their environment as ______ .
A. their wastes were covered over by nature
B. they were more careful and less greedy
C. their junkyards didn't grow tall yet
D. they had foresight and planning
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What is the writer's main purpose in the article？
A. To recommend regular physical exercise.
B. To describe the dreadful nature of the backache.
C. To suggest that back problems can be remedied.
D. To explain the widespread occurrence of back pain.
The solution to water pollution is ______ .
A. storing the sewage in a giant tank
B. dumping more sewage into the distant ocean
C. building more sewage disposal plants
D. replacing underground pipes full of sewage
According to the passage, the body appears to form. habits that ______ .
A. inevitably cause physical pain
B. can be difficult to change
C. are a consequence of actions we perform
D. develop in early childhood
According to the author, sadness responses are ______ .
A. brutal
B. avoidable
C. reasonable
D. harmful
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