女孩中枢性性早熟最常见的原因为（）
A.特发性
B.颅内肿瘤
C.原发性甲状腺功能减低症
D.肾上腺皮质增生症
E.食用含有雌激素的食物
参考答案：A
已知数列{an}的前n项和为Sn，且2Sn=3an-1，n∈N*
（I）求数列{an}的通项公式；
（II）求数列{nan}的前n项和Tn．
It is reported that we have produced _______ this year as we did last year.
A．as much cotton twice
B．twice as much cotton as
C．twice as much cotton
D．much as cotton twice
