我国人口分布的基本特点是（ ）
A：南方人口多，北方人口少
B：北方人口多，南方人口少
C：西部人口多，东部人口少
D：东部人口多，西部人口少
Mike is a boy. He is seven years old. His birthday is September 9. He is 1.4 metres tall. He lives in a house near the park. His address is 36 Park Road. He likes to read books on Sundays.
实验室里常用锌和稀硫酸反应来制取氢气．林辉同学取6.5g锌并加入50g一定质量分数的硫酸溶液，恰好完全反应后，得到56.3g硫酸锌溶液．发生反应的化学方程式是：
Zn+H2SO4═ZnSO4+H2↑．请你计算：
—Where's Sam?
—He _______ for a test in his room.
红军不怕远征难，万水千山只等闲。
五岭逶迤腾细浪，乌蒙磅礴走泥丸。
金沙水拍云崖暖，大渡桥横铁索寒。
更喜岷山千里雪，三军过后尽开颜。
——***《长征》
