则Ⅰ、Ⅱ、Ⅲ三种激素的名称分别是（　　）

两直线l₁与l₂平行可表示为____．

根据短文内容，从方框中选择适当的词并用其正确形式填空，使短文通顺、意思完整，每空一词，每词限用一次。

    My name is Betty. I am twelve. I have some ____. We are middle school students. We are in Class Two, Grade Seven. This is Miss Green. She is an American teacher. She ____ us English. Her classes are very ____. We all like her.

    This is my new classroom. In the classroom you can see many ____ and chairs. A blackboard, a clock and a map ____ China are on the wall. On a desk, you can see some pencils. The red one is mine. The green one is ____.

    Look! You can see a ball under the desk. That's Kate's desk. The ball is____, too. This is my desk. You can see a ____on it.

保护公民的合法财产，最严厉、最有效的保护方法是（    ）