12g与足量稀硫酸反应，生成氢气多少克?（反应的化学方程式为：Mg+H₂SO₄=MgSO₄+H₂↑）

    This is my family．This is my father．He is strong．He has short hair．He is a doctor．This is my mother．She is not fat．She is a nurse．She has long hair．This is my grandfather．He is tall．He is a farmer．Where is my grandmother? She is in the kitchen．Look，that is my little brother．This is my big family．

在一个密闭的保温装置中装有正在萌发的种子，每隔一段时间测定其内的温度和氧气含量，并将结果绘成曲线，如果横轴表示时间，纵轴表示温度和氧气含量，下列曲线能正确反映温度和氧气含量随时间变化的是（ ）