三年级上册英语第三单元中，“手”和“头”这两个单词的区别在于它们所表示的身体部位不同。
“手”通常指的是人类身体的上肢末端部分，具有抓握、操作物品等功能。在英语中，手的单词是“hand”，它是一个可数名词，通常用来表示单个的手或者双手。例如，我们可以说“I have two hands.”（我有两只手。）
而“头”则是指人类身体的上部，包含大脑、眼睛、耳朵、鼻子和嘴巴等重要器官。在英语中，头的单词是“head”，它也是一个可数名词，但通常用来表示单个的头。例如，我们可以说“She has a beautiful head of hair.”（她有一头漂亮的头发。）
总之，“手”和“头”这两个单词虽然都是表示身体部位的名词，但它们在身体中的位置和功能不同，因此它们的含义和用法也有所区别。
以下是一个三年级上册英语第三单元的小故事，供您参考：
Once upon a time, there was a little girl named Lily. She loved to sing and dance. One day, her mom took her to a children's party. There were many other kids there, and they were all having a great time.
Lily was shy at first, but then she saw a boy named Tom. He was wearing a red shirt and he looked very friendly. Lily walked up to him and said, "Hi, Tom. I'm Lily. What's your name?"
Tom smiled and replied, "My name is Tom. What do you like to do?"
"I like to sing and dance," said Lily.
"That sounds great!" said Tom. "Can you sing and dance for me?"
Lily nodded and began to sing and dance for Tom. He watched her carefully and applauded when she finished.
"That was great!" he said. "You're really talented."
Lily beamed with pride. She thanked Tom for his compliment and asked him what he liked to do.
"I like to draw," he said. "Do you want to see my drawings?"
Lily agreed, and Tom showed her his drawings. She thought they were amazing and told him so.
"Thank you," he said with a smile. "I'm glad you like them."
From that day on, Lily and Tom became good friends. They shared their talents and interests with each other and had a lot of fun together. Lily even asked Tom to teach her how to draw, and he was happy to help her.
This is a story about making new friends and discovering new interests. It shows that when we share our talents and interests with others, we can create meaningful relationships that bring us joy and happiness.
学英语背动词不难，只要掌握好口诀就行。三年级上册的动词口诀是：am, is, are，do, does, did，go, went, gone，come, came, come，eat, ate, eaten，see, saw, seen，get, got, gotten。这些动词是我们学习英语时最基础的，通过口诀的帮助，我们可以轻松记住它们的过去式和过去分词形式。记住这些动词口诀，就能够更好地理解和运用英语语法，提高自己的英语水平。要认真学习，不断练习，相信一定可以掌握好这些动词的用法。