The present invention provides a method for acknowledging RLC data packet transmission and an RLC AM entity sender. An epithelium improving agent which comprises coenzyme Q10, cysteine, vitamins A, C and E and a skin extract of a rabbit inoculated with a vaccinia virus as the main components. The user device accesses an application hosted in the public portion of the computer network. A dimension of a top face of any floating gate in a second or subsequent layer is smaller than a dimension of a bottom surface of the floating gate in the lowermost layer in at least one of a first direction parallel to the front surface of the substrate and a second direction crossing the first direction. A kit to assemble an electronic device comprises three substantially planar panels. The variety is botanically identified as Fragaria\xd7ananassa.