The invention contemplates a copolymer which is a graft or block copolymer useful to change wettability and surface characteristics of biological surfaces. A drive lever may be pivotally connected at one end thereof to the tailgate lever arm and pivotally connected at an opposite end thereof to a bell crank. The lock system further comprises a locking member disposed within the lateral aperture and which is slidable therealong between unlock and lock positions. The first curved portion has a first width in the direction perpendicular to the length direction of the strips, and extends in the length direction of the strips. In this manner, this method suppresses access to the external memory, thereby reducing noise.