题目

    The Great Fire of London started in the very early hours of 2 September 1666. In four days it destroyed more than three-quarters of the old city, where most of the houses were wooden and close together. One hundred thousand people became homeless, but only a few lost their lives.     The fire started on Sunday morning in the house of the King's baker(面包师)in Pudding Lane, The baker, with his wife and family, was able to get out through a window in the roof. A strong wind blew the fire from the bakery(房)into a small hotel next door. Then it spread quickly into Thames St小明想知道花生米的密度，为了使结果更准确，他选择了以下器材：烧杯、清水、天平和砝码、量筒、盐和玻璃棒，并完成了实验。（1）实验操作步骤如下：A．把一粒花生米放入装有清水的烧杯中，发现花生米沉入水中，这是因为花生米的密度 水的密度（选填“大于”、“小于”、“等于”）；B．往烧杯里的水中逐渐加盐，并用玻璃棒轻轻搅拌，直到花生米悬浮在盐水中为止；C．把天平放在水平台上，调节平衡后称出烧杯和盐水的总质量m1，如甲图所示，则m1= g；D．从烧杯中倒出一部分盐水到空量筒中，液面如乙图所示，则倒出盐水的体积为 cm3；E．用天平称出烧杯和剩余盐水的总质量m2= 44g。（2）通过以上数据分析，可得出花生米的密度为 kg/m3。（3）以上测量花生米的密度，用到的科学探究方法是（ ）A．控制变量法 B．转换法 C．理想实验法