7. It has been said that all one can do for a sprained ankle is leave it alone while it heals itself, ice it, and to lie with it in a slightly elevated position.
A. all one can do for a sprained ankle is leave it alone while it heals itself, ice it, and to
B. all one can do for a sprained ankle is leave it alone to heal itself, to ice it, and
C. all one can do for a sprained ankle is leave it alone while it heals itself, and then ice it and
D. the only thing that can be done for a sprained ankle is leave it alone while it heals itself, ice it, and D
E. the only thing that can be done for a sprained ankle is to leave it alone while it heals itself, to ice it, and
C为什么错误？ | 
