24 如圖所示桿件受軸向外力作用,F1 = 100 kN,F2 = 500 kN,則 A、B 處反力大小為何?(A)= 250 kN, = 350 kN (B) = 270 kN, = 330 kN (C) = 290 kN, = 310 kN (D) = 350 kN, = 250 kN(E)一律給分