苯妥英钠抗癫痫的治疗血药浓度为（） A.4～12mg B.5～12mg C.10～2

教育目的的制定，教育经费的分配，教育内容的规定，教育行政人员和教师的任命、聘用等，反映了政治经济制度决定()

A．教育的领导权

B．受教育的权利

C．教育的目的

D．教育的独立性

Dear editor,

I am a high school student. A few days before, one of my very good friends told me that he was going to stop the school. He said that he want to start his own business. I tried my best to get him change his mind, but failed. I know it is difficult of him to change his mind. He is not doing so good in his studies, yet I want to insist that I give it a try. The process is more important than the results. Now there are only 90 days leaving before the test. I am not sure that his decision is right or wrong. I needed your advice.

在下列溶液中，各组离子一定能够大量共存的是 [ ]

A．使酚酞试液变红的溶液：Na⁺、Cl^-、SO₄^2-、Fe³⁺

B．含有大量Al³⁺的溶液：Na⁺、NH₄⁺、SO₄^2-、Cl^-

C．含有大量Fe³⁺的溶液：Na⁺、Mg²⁺、NO₃^-、SCN^-

D．碳酸氢钠溶液：K⁺、SO₄^2-、Cl^-、H⁺

材料在自然状态下单位体积的质量为( )。

A．表观密度

B．密实度

C．孔隙率

D．密度

以下是葡萄糖耐量因子的重要成分的是（）。

A.锌

B.硒

C.碘

D.尼克酸

E.叶酸