Based on the table, one advantage to using 2×10 boards rather than 2×8 boards is that: at a given load, the 2×10 boards can support a smaller span. at a given load, the 2×10 boards can support a greater span. at a given spacing, the 2×10 boards require less construction time. at a given spacing, the 2×10 boards require less construction cost.

the answer is:  

he is voicing feelings shared by all humans regardless of race.

in paul laurence dunbar's poem "we wear the mask," he replicates the words mask and we to emphasize how people in general -not just black americans- hide their true feelings. he suggests the masks cover people's faces and eyes, which are the main parts that display their emotions. he also thinks people's pain conceal behind those masks, so that they cannot see reality and nobody is able to see one another's sorrow.