backwardness

n.落后(状态)

backlash, backless, backlist, backlog, backpack, backpacker, backpacking, backrest, backscratcher, backset, backside, backslide, backsliding, backspace, backstage, backstroke, backtrack, backup, backward, backward(s), backwards, backwards (also backward), backwash, backwater, backwoods, backwoodsman, backyard, bacon, bacteria, bacterial, bactericidal, bacteriologist, bacteriology, bacterium, bad, bad debt, bad lands, bad language, bad-mouth, bad-tempered,