下述哪项是抗甲状腺药物治疗甲亢中最常见的并发症（）
A.药疹
B.肝功能损害
C.白细胞减低
D.甲状腺功能低下
E.胃肠道反应
参考答案：C
等腰三角形一边长是3cm，另一边长是6cm，则它的周长是______．
I _____ to him. He is too serious. [ ]
A. didn't use to talk
B. am not used to talking
C. am not used to talk
D. didn't use to talking
