测定食品中的硒，消化处理至终点冷却后，为使六价硒还原成四价硒

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问题单项选择题

测定食品中的硒，消化处理至终点冷却后，为使六价硒还原成四价硒，需要加入以下哪种物质后继续加热（）

A.硫酸

B.盐酸

C.硝酸

D.氰溴酸

E.高氯酸

答案

参考答案：B

解析：某些含硒较高的蔬菜中含有较多的六价硒，需要在消化终点时冷却，然后加入10ml盐酸溶液，继续加热使六价硒还原为四价硒。

完形填空

根据括号内的英(汉)语提示，完成句子。

小题1:Nothing can prevent us from (realize) our “Chinese Dream”.

小题2:Unfortunately he had his left leg (break) in the high jump last week.

小题3:My grandmother often falls (睡着) when she watches TV.

小题4:Tom (write) his lessons when he heard a terrible noise outside.

小题5:Mary has curly hair and she is of medium (高度).

小题6:Lucy often (刷) her teeth after meals.

小题7:We have walked for a long time. Let’s stop (have) some water.

小题8:— you ever (be) to an amusement park?

—Yes, I have.

小题9:— What kind of noodles would you like ?

— I’d like some (牛肉) and tomato noodles, please.

判断题

计算机显示器的分辨率越高意味着屏幕显示的精度越高，显示出来的对象尺寸也越大。( )