China Driving Subject 4 (Motorcycle) Practice Questions - China Motorcycle Driver's License Subject 4 Examination (机动车驾驶人科目四 安全文明驾驶常识 - 摩托车) Exam

By acting like a high-tension spring that bounces the rider's head back to its original position instantly By absorbing sweat and ventilating engine heat away from the scalp without undergoing physical changes By permanently crushing and deforming microscopically to absorb kinetic energy and extend deceleration time, reducing peak G-forces transferred to the skull By hardening into a rigid solid block upon impact to prevent the outer shell from flexing