It’s these ultraviolet rays that have sunk your delicate skin

_1 It’s these ultraviolet rays that have sunk your delicate skin Judging from the current progress of scientific research, the primary reason for sunburning human skin is natural ultraviolet rays. Ultraviolet rays are distinguished according to their wavelengths: three types are ultraviolet C (200-280nm), ultraviolet B (280-320nm), and ultraviolet A […]