格列佛在利立普特受到优待，作为条件他必须做什么？（    ）

某校课外兴趣小组在本校学生中开展对“消防安全知识”了解情况的专题调查活动，采取随机抽样的方式进行问卷调查，调查的结果分为A，B，C，D四类．其中，A类表示“非常了解”，B类表示“比较了解”，C类表示“基本了解”，D类表示“不太了解”，划分类别后的数据整理如下表格：

（1）根据表中数据，问在关于调查结果的扇形统计图中，类别为B的学生数所对应的扇形圆心角的度数为多少？

（2）若A类学生数比D类学生数的2倍少4，求表中a，m的值；

（3）若该校有学生955名，根据调查结果，估计该校学生中类别为C的人数约为多少？

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!