Internet in creating handheld computers is fueled by the desire to shrink the size of the electronic circuitry and to create exceptionally small mechanical systems. At this scale, however, physical (i)____________ poses unique challenges. Machining, positioning, and assembling parts by hand are easy at macroscopic scales but at minute scales they are far from (ii)____________. A. deterioration B. subtle C. manipulation D. inflexible E. durability F. routine