总体
参考答案：
总体是我们所研究的具有某种共同特性的个体的总和。样本是从总体中抽出的作为观察对象的一部分个体。
读短文，判断正(√)误(×)。
I'm Alice. This is our school. It is big. This is my classroom. It's big and clean. Look! That is my desk. It is
yellow. My teacher is Miss Li. She is in the classroom. She is a good teacher. I like my teacher.
( ) 1. My name is Alice.
( ) 2. My school is small.
( ) 3. My classroom is dirty (脏的).
( ) 4. My desk is yellow.
( ) 5. Miss Li is not in the classroom.
电气绝缘安全用具怎样分类？
