张先生,56岁,患有食管癌,经检查无转移属于早期食管癌,治疗应选用()
A.化疗
B.放疗
C.姑息术
D.根治手术,辅助化疗和放疗
E.根治手术
参考答案:D
顶角是30。的等腰三角形,每个底角是( )。;等边三角形每个内角都是( )。。
He _____stay at home and looked after his mother yesterday.[ ]
A. needed to
B. has to
C. have to
D. needs to