骨肿瘤最基本的影像学检查是()。
A.X线片
B.CT
C.MRI
D.ECT
E.血管造影
参考答案:A
--- I’m very tired these days.
--- Why not ______ music? You will feel ______.
A.listen to; relaxed
B.listening to; relaxing
C.listening to; relax
D.listen to; not relax
已知函数f(x)=x2(ax+b)(a,b∈R)在x=2时有极值,其图象在点(1,f(1))处的切线与直线3x+y=0平行,则函数f(x)的单调减区间为______.