以下属于牙髓电活力测验禁忌症的是
A．甲状腺机能亢进症
B．冠心病
C．高血压
D．装心脏起搏器者
E．癫痫病
参考答案：D
Because the driver was not ________ the new limit, he was stopped and warned for speeding.[ ]
A. good at
B. tired of
C. aware of
D. interested in
设(a≠0)，令a1=1，an+1=f(an)，又bn=an·an+1，n∈N+．
(1)判断数列是等差数列还是等比数列，并求数列(an)的通项公式；
(2)求数列(bn)的前n项和．
(a≠0)，令a1=1，an+1=f(an)，又bn=an·an+1，n∈N+．
是等差数列还是等比数列，并求数列(an)的通项公式；