MRI与CT相比,下列哪项不是其特点
A.对火器伤诊断价值高
B.造影剂安全系数较大
C.直接多轴面成像
D.对钙化和骨质结构不敏感
E.无射线损伤
参考答案:A
比a的2倍少3的数的相反数用代数式表示为______.
China's reform and opening has been going on for ________ is like about 30 years now and it's really quite remarkable.
A.that
B.which
C.what
D.it