“工农武装割据”思想的内容是（）
A.城市暴动
B.土地革命
C.武装斗争
D.根据地建设
E.农民起义
参考答案：B, C, D
在一间壁换热器中，两流体均在湍流下进行换热。冷热流体的对流传热系数分别为150kW/(m2·℃)和300kW/(m2·℃)。若只使某一侧流体的流速加倍以强化传热，对流总传热系数增加的最大百分数与( )接近。(可按平壁处理，忽略管壁热阻，污垢热阻和热损失)
A．(A) 16%
B．(B) 20%
C．(C) 40%
D．(D) 50%
An analyst does research about margin transaction. An investor purchases common shares at $ 25 per share on margin and deposits just enough money to cover the 65% initial margin requirement. If the maintenance margin requirement is 30%, the share price below which the investor will first receive a margin call is closest to:（）
A. $11.54
B. $12.50
C. $19.70
