胆固醇不能转变为
A.雄激素B.雌激素C.醛固酮D.胆色素E.维生素D3
参考答案:D
解析:胆色素是体内铁卟啉代谢产物,和胆固醇不相干,不能由胆固醇转变。
Police have asked witnesses of the accident to ___________, as the victim is critically wounded, unable to give an account of the accident.
A.come by
B.come across
C.come forward
D.come on
软X线摄影主要是利用X射线的
A.光电吸收B.康普顿吸收C.电子对效应D.光核反应E.相干散射