lucrative adj. 赚钱的，有利可图的(profitable;remunerative)

　　[记]词根记忆：lucr(看作lucre钱财)+ative→赚钱的

　　[例]Burdened by debt, Lydgate abandons his dreams of reforming medicine to take a conventional but lucrative practice in London.

　　[同]advantageous, gainful, profitable, remunerative

　　ludicrous adj. 荒唐可笑的(so foolish as to cause disrespectful laughter)

　　[记]词根记忆：lud(玩)+icrous→闹着玩的→可笑的

　　[例]Although his attempts to appear psychotic were so clumsy as to be almost ludicrous , there is evidence that Ezra Pound was able to avoid standing trial for treason merely by faking symptoms of mental illness.

　　[同]laughable, comic, comical, droll, farcical

　　lugubrious adj. 悲哀的(mournful);忧郁的(dismal)

　　[例]Much of the clown’s success may be attributed to the contrast between the lugubrious manner he adopts and the general hilarity that characterizes the circus.

　　[同]melancholy, dolesome, dolorous, lamentable, plaintive

　　luminous adj. 发光的(emitting or reflecting usually steady, suffused, or glowing light);发亮的(of or relating to light or to luminous flux);光线亮的(bathed in or exposed to steady light);明白易懂的(clear, enlightening);有光泽的(shining, illustrious)

　　[记]词根记忆：lumin(光)+ous→发光的

　　[例]Although supernovas are among the most luminous of cosmic events, these stellar explosions are often hard to detect, either because they are enormously far away or because they are dimmed by intervening dust and gas clouds.