题目内容：
What’sthereasonfortwinstobeatadisadvantageintheirintellectualdevelopment?
A．Theycanonlyunderstandtheirownprivatelanguage． B．Theycommunicatewithoutsiderslessthannon-twins．
C．Thereislittlestimulationforthem．
D．Adultsdon’tliketotalkwiththem．
参考答案：
答案解析：