①分解因式:x2+2x+1=( ).
②若∠ α=40 °,则∠ α的余角是( )度.
(1)(x+1)2;(2)50°
关于Caroli病的CT表现,错误的是()
A.肝内胆管扩张,右叶为主
B.肝门区中心胆管不扩张
C.肝内多个小囊状区域,与肝内胆管不连接
D.扩张的肝内胆管可有小结石影
E.肝硬化表现
An awful traffic accident did, the other day,_________ in the street. [ ]
A. occurred
B. occur
C. occurred to
D. occur to