X线和CT使用的离子型对比剂的溶液中含有 ()
A.等离子
B.负离子
C.氧离子
D.臭氧离子
E.阴离子和阳离子
参考答案:E
Now since the assessment of intelligence is a relative matter we must be sure that the scale with which we are comparing our subjects provides valid or fair comparison.
A.comparable
B.comparative
C.competitive
D.compatible
承轨面与钳口面夹角允许误差是()。
A、±5度
B、±1度
C、±2度
D、±3度