2. Grass-mouse-snake-eagle

3. Grass-mouse-eagle

4. Grass-Rabbit-Eagle

You can write all these animals and plants on paper, with plants as producers in the middle and animals around them.

What you eat is connected by arrows, and every time you count it from the producer to the highest consumer, it is a food chain.

But pay attention to advanced consumers, such as the eagle in the example, which can eat both rats and snakes. Therefore, it can be connected behind the grass mouse snake to form a food chain, or it can be directly connected behind the grass mouse to form another food chain.

I hope the brothers downstairs don't talk nonsense. A complete food chain must start from the producer and reach the highest nutritional level that the chain can reach. Moreover, in the conditions given in the example, birds don't eat grass and snakes don't eat birds.