Cause and Effect

Grade 3 Reading Worksheet

Circle the answer.

1. Read this first

   How Beavers Change a Stream

   A beaver is a large animal with strong front teeth. It lives in and near streams. Beavers are famous builders. Their work can change a whole stream.

   Beavers need deep, still water to stay safe. In deep water, they can swim away from danger. They can also keep the doorway of their home under water. But many streams are shallow and fast. So beavers build a dam.

   First, a beaver cuts down small trees with its teeth. Then it drags the branches into the stream. It packs mud and stones between the sticks. Slowly, the dam blocks the moving water. As a result, the water backs up and forms a pond.

   The new pond changes life around it. Fish and frogs find quiet water to live in. Ducks and herons come to visit. Plants grow along the wet edges. Because the pond holds water, the land nearby stays green even in dry summers.

   Dams can cause problems too. Sometimes the pond spreads onto a farmer's field or a road. Then people may have to move the beavers to a new place.

   When beavers leave, no one repairs the dam. Water leaks through the sticks, and the pond slowly drains. Grass fills in the rich, muddy ground. Years later, the old pond can become a flat, grassy meadow.

2. 1.

   Why do beavers need deep, still water?

   • It helps them stay safe.
   • It keeps their teeth strong.
   • It is warmer in the winter.
   • It brings ducks and herons.
3. 2.

   Why do beavers build a dam?

   • They need to keep the land green.
   • Farmers want water for their fields.
   • Many streams are shallow and fast.
   • They want ducks and herons to visit.
4. 3.

   What happens as a result of the dam blocking the water?

   • The trees along the stream grow back.
   • The water leaks out through the sticks.
   • The water backs up and forms a pond.
   • The stream runs faster than before.
5. 4.

   Which is an effect of the new pond on animals?

   • Frogs move to the grassy meadow.
   • Fish swim away to faster water.
   • Ducks and herons leave the area.
   • Fish and frogs find quiet water.
6. 5.

   Why does the land near a beaver pond stay green in dry summers?

   • Herons carry seeds there.
   • The stream runs faster.
   • Beavers plant grass there.
   • The pond holds water.
7. 6.

   What may happen if a beaver pond spreads onto a road?

   • The road may turn into a meadow.
   • Farmers may plant trees on it.
   • Beavers may build a second dam.
   • People may move the beavers.
8. 7.

   What causes the pond to drain after the beavers leave?

   • The fish and frogs move to a new pond.
   • A dry summer dries up all the water.
   • The dam is not fixed, so water leaks out.
   • Farmers cut a hole in the dam.
9. 8.

   What does "backs up" mean in "the water backs up and forms a pond"?

   • freezes into a sheet of ice
   • flows away quickly downstream
   • rises and spreads behind the dam
   • turns into thick mud
10. 9.

    Which list shows the events in the right order?

    • Dam is built, meadow grows, pond forms, pond drains.
    • Dam is built, pond forms, pond drains, meadow grows.
    • Pond forms, dam is built, meadow grows, pond drains.
    • Meadow grows, dam is built, pond drains, pond forms.
11. 10.

    Which words in the third paragraph tell you an effect is coming?

    • First
    • Slowly
    • As a result
    • Then