题目

由乙烯推测丙烯的结构或性质，正确的是       （    ）       A．分子中三个碳原子在同一直线上        B．分子中所有原子在同一平面上       C．与HCl加成只生成一种产物               D．能发生加聚反应  答案：D解析:  A storm dropped heavy rains on central and southern parts ofChina.The radio says that a 1      the Xiangjiang River in Hunan，flood  caused by terrible  r  2       in the past weeks killed 25 people and 13 others were missing.The Chinese government warned some parts in Yunnan and the city of Chongqing of possible heavy rains over the f 3      few days.In Changsha,water levels rose(水位上升）to 38 metres early Monday morning,about 3 metres a 4      the danger line.In Guangdong,at 1 5       21 people have been killed,while three  were s  6       hurt  and  seven went missing w 7      heavy floods hit northern parts by Saturday.The cities of Shaoguan，Meizhou and Heyuan w 8      hardest hit and many people were left homeless (无家可归的）.About 620 million yuan has been lost in the floods. The local government of Guangdong has sent something h 9      to Meizhou,Heyuan and Shaoguan to help the people who had lost homes build their h 10      again.1.          2.          3.      4.       5.          6.          7.          8.      9.       10.