In addition, the dirt adhering to the surface and sunken of rubber stopper has some conglutination;it is not easy to clean away by dipping in cleaning liquid.

• 另外，粘附在胶塞表面和脐眼深处的脏物均具有一定的粘附强度，不易在清洗液中一泡就能自动被剥离清除掉。