三、操作与实践。
1. 在下面方格纸上画一个以AB为底的任意三角形。
2. 在底边AB上作出这个三角形的一条高。

1. 在AB边的上方任意选取一个不在AB所在直线上的格点C，顺次连接点A、点C、点B，得到三角形ABC。
2. 过点C向底边AB作垂直线段，使垂足落在AB边上，在垂足处标注直角符号，该垂线段就是AB边上的高。
答：按上述步骤操作即可得到符合要求的图形。

1.一块等腰三角形菜地，底边长为27.8米，腰长为20.2米，这块菜地的周长是多少米？

1. 68.2米

2.第一小组6名学生数学测验的成绩分别是86分、79分、98分、100分、89分、94分，他们的平均分数是多少？

2. 91分

一、根据语境从括号内两个选项中选择最佳选项补全短文。
This is my 1 (A. father B. aunt). He often works in the 2 (A. fire station B. fields) and he 3 (A. use B. uses) his brush a lot. But he is not a 4 (A. painter B. writer). He is a 5 (A. scientist B. cook).
1. 2. 3. 4. 5.

1.A 2.B 3.B 4.A 5.A

二、瑶瑶读了一篇科普小短文。阅读短文，判断句子正(T)误(F)。
Our feelings can be like colours! When you feel angry, it is like a huge red fire. Feeling happy can be bright yellow like the sun. Feeling sad might be grey（灰色）like a cloudy sky. When you feel worried, it can feel dark like the night. Music shows feelings too! Sad music is often slow and quiet. Happy music is often fast, high and loud. Angry and exciting（令人兴奋的）music can also be loud and fast.
()1. Music and colours can show feelings.
()2. When you feel angry, it can be like a huge red fire.
()3. Happy music is slow, high and loud.
()4. Angry and exciting music can be loud and fast.

1.T 2.T 3.F 4.T