阅读下列材料，回答问题。

材料一在鸦片战争后新开放的通商口岸中，最重要的是上海……上海在半殖民地半封建的中国居于特殊的地位，它是资本主义——帝国主义侵略中国的一个最大的桥头堡垒。

——《从鸦片战争到五四运动》（上）

材料二(1972年)二月二十八日，双方在上海正式签订并发表了《联合公报》，《联合公报》的发表，在中美关系发展史上有着里程碑的意义。它标志着两国从长期尖锐对立开始走上关系正常化的道路，为以后两国关系的进一步改善和发展打下了基础。

——《二十世纪中国史纲》

材料三

图6

由于国际原油价格不断攀升，国家的关部门决定扩大“乙醇汽油”的试点范围.乙醇可用高梁.玉米.薯类为原料，经过发酵蒸馏制得.同时，由于能源价格的上涨，昔日常用的蜂窝煤因价格低廉又受到人们的青睐.请回答：

根据短文内容，选择最佳答案。

A

    Do you like blueberries? But maybe you don't know blueberries well.

    Farmers often grow them on bushes(灌木丛) in the field. A blueberry is small and round. Many blueberries can grow on one bush. At first, the blueberries are green. You can't eat the green berries. A lot of sun and rain help them become sweet. When the berries become blue and big, they are ripe and sweet.

    After the blueberries are ripe, people put them into boxes and bring them to stores and supermarkets. People buy the blueberries and take them home to eat. After they wash the berries, they eat them one by one. Some people like to cook with blueberries. They make blueberry muffins(松饼) and pancakes. They like to make blueberry juice. Others like to make blueberry ice cream. It is very cool!