{{B}}quEstions 16 to 20 ArE BAsED on thE Following tAlk.{{/B}}

A、suFFErErs From BACk pAin ArE not ABlE to movE ArounD、
B、it is usuAlly BEttEr At sElF-rEpAir.
C、A、BACk injury is usuAlly morE pAinFul.
D、its rEsponsE to injury oFtEn rEsults in morE DAmAgE.