most children nowadays are the only chidren, they tend to be more self-centered．
A. Ever since
B. Now that
C. Only if
D. Even though
网友回答
A. Ever since
(答案→)B. Now that
C. Only if
D. Even though
解析：短语辨析。 A．从那时到现在 B．既然；由于 C．只要……就 D．虽然；即使。句意：由于当今大部分孩子都是一个，他们更倾向于以自我为中心。故选B。