A heavy learning burden leads to unhealthy behaviors such as poor eating habits, which damage the health of students.
A. in its turn
B. in return
C. in turn
D. by turns
网友回答
A. in its turn
B. in return
(答案→)C. in turn
D. by turns
解析：考查介词词组： in return做为回报，in turn依次by turns轮流，句意：繁重的学习负担导致不健康的行为象，饮食习惯差，这反过来破坏学生的健康。选C。