This potential array plays a trap-like role in acceleration or buffering free charge carriers, causing the carriers to move toward the sieve holes, named as “sub-macro potential trap array”.
The Second Floor of the library in Clean the Library only has 6 sections: 2A, 2B, 2C, 2D, 2E, and 2F. See the table below to learn which category (and books) go in which section.