在用天平和量筒测量某种食用油的密度时，以下操作中，不必要且不合理的是（ ）
A：用天平测出空烧杯的质量
B：取适量的油倒入烧杯中，用天平测出杯和油的总质量
C：将烧杯中的油倒入量筒中，测出倒入量筒中油的体积
D：用天平测出烧杯和剩余油的总质量
There is a new park near my house. My family often go to the park on the weekend. There aren't any tall buildings in the park. There is a big lake in the park. But we can't swim in the lake. There are many flowers and trees near the lake. There is a small hill behind the lake. Beside the lake, there is a small shop (商店). The park is beautiful. I like it very much.
世界人口稠密地区多位于（ ）
