现有a、b两份质量相等的氯酸钾，其中一份加入二氧化锰，同时加热，生成气体的质量与时间关系如右图所示，下列说法不正确的是（    ）

    I'm Sally.I have three new teachers.A Chinese teacher，a maths teacher， and an art teacher.My Chinese teacher is Miss Zhang.She's pretty and young.My maths teacher is Mrs Liu.She's tall and thin.My art teacher is Mr Sun.He's tall and strong.He's very kind.