If he had been taken good care of at that time, the boy ___ now.

A．will not be sick

B．would not be sick

C．could not have been sick

D．isn’t sick

对于无腹筋梁，剪跨比和受剪承载力的关系为（）。

A.剪跨比越大，受剪承载力越低

B.剪跨比越大，受剪承载力越高

C.剪跨比和受剪承载力没关系