liFE ExpECtAnCy Among ADults 45 AnD 65 yEArs oF AgE By FAmily inComE, sEx, AnD rACE: unitED stAtEs, AvErAgE AnnuAl 1979-89



in thE FigurE ABovE, thE DiAmEtEr oF thE CirClE is 20 AnD thE ArEA oF thE shADED rEgion is 80π. whAt is thE vAluE oF A + B + C + DA．144
B．216
C．240
D．270
E、288