冠状动脉粥样硬化,最常受累的动脉分支是
A.右冠状动脉主干
B.左冠状动脉主干
C.右冠状动脉回旋支
D.左冠状动脉回旋支
E.左冠状动脉前降支
参考答案:E
— Could you help me _____ this Math problem, Lin Tao? It's too hard for me?
— OK. Let me have a try. [ ]
A. look after
B. work out
C. think of
D. put on
核酸中含量相对恒定的元素是
A.碳
B.氢
C.氧
D.氮
E.磷