白亮带形成原因是电磁搅拌产生的()沿凝固前沿流动,把两相区树枝晶间富集的母流冲刷出去而造成的。
参考答案:流股
The meaning of the word "nice' changed a few tines it finally came to include the sense "pleasant."
A.before
B.after
C.since
D.while
乙醇作为片剂的润湿剂一般浓度为( )。
A.30%~70% B.1%~10% C.10%~20%D.75%~95% E.100%