3.
You'll be weaving "through and around", as opposed to the "over and under" in traditional weaving. Begin by weaving strip 1 through slit A, around strip B, through slit C. Push this row to the back, where the slits end. Continue the weaving with strip B. Weave it through slit 1, around strip 2, through slit 3. Continue until all the rows are done.