After her son’s death, the old lady __________ sit at the window, deep in thought.

A．would

B．should

C．could

D．might

泰构件受拉区钢筋面积为2000mm²，同一截面内绑扎接头钢筋截面面积允许的最大值是（）。

A.500mm² 

B.600mm² 

C.800mm² 

D.1000mm²