naoyixue wrote:
in the material, author just concluded that people's voluntary choice not to exercise places a significant burden on society. meaing that the burden depends on the choice from people. It's selective. While, via C, we get to know, it does not depend on people's choice. the decision not to do exercise depends on the physical condition ( such as require medical or nursing-home care ). So we get to know not the people's choice casue more cost on the society, but the phsycial condition.
For A, it
...
![FLO – Therapy at the Club – Pre-Single [iTunes Plus M4A]](http://is1-ssl.mzstatic.com/image/thumb/Music221/v4/a4/11/88/a41188ed-0f2e-e8d5-1163-d59e373cc58c/26UMGIM30046.rgb.jpg/208x208bb.webp)
