B

    You may know the English letters A, B and C, but do you know there are people called "ABC"? You may like eating bananas, but do you know there are people called "banana persons"? If you don't know, I will tell you about it. They are some Chinese people like you and me, but they aren't in China. Why do people call them like that?

    If we call somebody an ABC person, we mean he or she is a Chinese but was born in America. Sometimes, people also call them "banana persons". A banana is yellow outside and white inside. So if somebody is a "banana person", he or she is "white" inside and "yellow" outside. By saying that, we mean he or she has yellow skin(皮肤) but does things in an American way. "Banana persons" were born in America and they live in America for a long time, so they think like Americans and do things like Americans. However, these people still have Chinese blood(血统). Their parents, grandparents or even great-grandparents are from China. They all have black eyes and black hair, so they look like us, Chinese people.

    There are many famous "banana persons" in America. They do very well in America and they are really great in their own fields.

读亚洲大陆沿30°N地形剖面图，回答图中的甲乙丙丁分别代表的地理事物名称是（    ）

 为了测量一小块矿石的密度，小丽利用一个弹簧测力计、水和一段细线进行了如下实验：