Proper exercise is good for your health._____, too much is bad for it.
A. Therefore B. But C.However D. while
Proper exercise is good for your health._____, too much is bad for it.
A. Therefore B. But C.However D. while
C
考查副词的用法。由空格后的逗号看出，此处需要一个副词，依据句意表转折，故选C；but和while都是连词。