问题 填空题

(7分)目前木糖醇口香糖正在取代蔗糖口香糖。请根据资料回答问题:①木糖醇甜度相当于蔗糖、易溶于水、是白色固体(20℃、30℃、50℃、60℃溶解度分别为60g、70g、84g、90g)②人的口腔中唾液的pH为6.6~7.1,若酸性增强会形成龋齿。

(1)木糖醇具有的物理性质是                      (任写一点)

(2)图1中a点表示的含义是                      ,画出木糖醇的溶解度曲线。

(3)由图2可知咀嚼木糖醇口香糖比蔗糖口香糖      (选填“有”或“不”)利于牙齿健康,原因是                                                               

答案

(1)易溶于水或白色固体;(2)50℃时,X、Y两种物质的溶解度相同或相等;

(3)有;在口腔细菌的作用下,咀嚼木糖醇分解产物比咀嚼蔗糖分解产物的酸性更弱,更利于保护牙齿。

题目分析:(1)根据题意可知,木糖醇的物理性质有:易溶于水或白色固体;

(2)a点是X、Y两种物质溶解度曲线的交点,所以可表示在50℃时,X、Y两种物质的溶解度相同或相等;可根据题目提供的“20℃、30℃、50℃、60℃溶解度分别为60g、70g、84g、90g”进行做图像。

(3)根据图2可知:在口腔细菌的作用下,咀嚼木糖醇分解产物比咀嚼蔗糖分解产物的酸性更弱,更利于保护牙齿。

问答题

阅读下列材料,回答问题。

       回顾中国近代史,国共两党关系决定了中国政局,两党合作与分裂都对中国革命进程产生了重大影响。

请回答:    

(1)为推翻北洋军阀的反动统治,中共对国民党采取什么政策?结果如何? 

                                                                                                                                                            

                                                                                                                                                             

(2)1927年,针对国民党的屠杀政策,中共采取什么政策?毛 * * 找到一条什么样的革命道路? 

                                                                                                                                                             

                                                                                                                                                             

(3)随着日本不断侵略中国,中共对国民党采取什么政策?有何作用? 

                                                                                                                                                             

                                                                                                                                                             

(4)抗日战争胜利后,中共对国民党采取什么政策?为什么要采取这样的政策?结果怎样? 

                                                                                                                                                             

                                                                                                                                                             

                                                                                                                                                             

(5)从国共两党关系看,我们可以得出怎样的历史经验和教训?

                                                                                                                                                             

                                                                                                                                                             

单项选择题