-- Jack, I haven't seen your uncle for a long time.

-- He _____ Shanghai on business for two mouths.

△ABC中，∠C=∠B，D、E分别是AB、AC上的点，AE=2cm，且DE∥BC，则AD=____cm．

听短文，在短文中填写所缺单词
    Tom is a____boy. He is eleven years old. He's two years younger than his____, Jim. Tom is 150cm and Jim is 160cm. Jim is 50 kilos and Tom is 60 kilos. Tom wants to lose some weight, so he tries not to eat too much____. He also____more exercise than____.
    ____morning he gets up earlier than Jim and he goes____for____minutes. He usually does it after school. After dinner, Tom often goes for a ____, and Jim likes____at home. Now Tom is much____than Jim. Jim thinks he____more exercise now. He and Tom will do exercise tighter.

形成基本的化学观念是初中化学重要的学习目标之一，也是初中阶段应该具备的化学素养，下列事实或现象包含了﹣些基本化学观念．请根据要求合理回答：

（1）墙内开花墙外香，从微观分析其原因是：____．

（2）现有初中化学常见的五种物质：①Mg；②CH₄；③稀硫酸；④CuO；⑤KMnO₄．请按单质、氧化物、盐、有机物、混合物顺序排列为　____ （填序号）．

（3）几千万年前一条恐龙体内的某个原子可能在你的身体里．原因是：____ ．

（4）化学物质具有两面性：一方面为人们的生活带来了无数便利；另一方面它也对人类生存的环境造成种种危害．请举例并说明其两面性____ ．

某种细菌经60分钟培养，可繁殖为原来的2倍，且知该细菌的繁殖规律为y=10e^kt，其中k为常数，t表示时间（单位：小时），y表示细菌个数，10个细菌经过7小时培养，细菌能达到的个数为   (   )