【判断题】在重结晶操作中,溶解样品时要判断是否存在难溶性杂志,可以先热过滤,再对滤渣进行处理。
【单选题】Which of the following statements is NOT true about the service industry in the United States?
A.
Financial sector is at the heart of the American service industry.
B.
American service industry provides one third of the world labor force.
C.
American service industry is highly customized.
D.
It is not easy to innovate and upgrade the service industry.
【简答题】A characteristic of the information age is that ________. A) the service industry is relying more and more on the female work force B) manufacturing industries are steadily increasing C) people find i...
【单选题】引起药物不良反应的机体方面原因是
E.
种族差别、性别、年龄、个体差异、病理状态、血型、营养状态
【简答题】智力的群体差异表现在_______ 、_______ 和种族差异上。
【多选题】下列有关位错的说法中,错误的是
A.
刃型位错与螺型位错的位错线运动的方向均与位错线垂直。
B.
晶体发生塑性变形会导致位错的运动、位错的增殖和交割。
D.
负刃型位错的滑移面之下的原子间距变大,晶格受到拉应力。
【判断题】在重结晶操作中,溶解样品时要判断是否存在难溶性杂质,可以先热过滤,再对滤渣进行处理。