问题 判断题

气敏电极法测定环境空气中氨时,配制氨标准储备液,应取分析纯的NH4Cl经105℃干燥后按要求配制。

答案

参考答案:

解析:应取优级纯的NH4Cl。

识图题:

请回答:

(1)以上图片反映了开国大典情况,请你为图一毛 * * * * 配上一句话。并指出图二、图三分别反映了

    开国大典的什么情景?

                                                                                                                                                            

                                                                                                                                                            

                                                                                                                                                            

(2)以上图片所反映的历史事件距我们今天多少周年?

                                                                                                                                                            

(3)结合所学指出上述图片所反映的历史事件的伟大历史意义?

                                                                                                                                                            

                                                                                                                                                            

                                                                                                                                                            

单项选择题 A1/A2型题