若△ABC的三边长分别为a,b,c,则下列条件不能推出△ABC是直角三角形的是[ ]
A.a2﹣c2=b2
B.∠A+∠B=∠C
C.a2+b2=2ab
D.∠A=2∠B=2∠C
答案:C
I usually clean my bedroom ______________ Saturdays. [ ]
A. at
B. to
C. on
D. in
散寒止痛,治虚寒腹痛泄泻宜选
A.吴茱萸
B.丁香
C.肉桂
D.附子
E.干姜