硫印检验可以分析钢中硫化物分布情况。
参考答案:对
In that school, English is compulsory for all students, but French and Russian are________.[ ]
A. special
B. regional
C. optional
D. original
下列哪种药物对肾及肠系膜血管扩张作用最强
A.异丙肾上腺素
B.间羟胺
C.麻黄碱
D.多巴胺
E.肾上腺素