对检出转移性骨肿瘤最敏感且无假阳性的方法是（）
A.CT
B.MRI
C.X-ray
D.核素
E.DSA
参考答案：B
A computer with ten thousand books ____ to a school in a mountain village as a gift.
A. has offered B was offered C. are offered D. have offered
联轴器只有在机器停车时，用拆卸的方法才能使两轴()。
A、脱离传动关系
B、改变速度
C、改变运动方向
D、改变两轴相互位置
