Cause and Effect — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. The farmer noticed that rabbits had eaten all the lettuce in the garden. He decided to build a fence around it. What was the cause of the farmer building a fence?
A) The farmer liked building things.
B) The lettuce was ready to pick.
C) Rabbits ate all the lettuce.
D) The fence was made of wood.
The fence is the effect, built in response to a problem. The lost lettuce is what made the farmer take action to keep rabbits out of the garden.
2. Which signal word best completes this sentence? "___ the temperature dropped below freezing, the lake turned to ice."
A) So
B) Therefore
C) But
D) Since
'Since' is capitalized to start the sentence with the cause. Water freezes solid below 32 degrees, which is why the lake turned to ice.
3. Noah left his bicycle outside all winter without a cover. In the spring he found that the chain was rusty and the tires were flat. What was the effect?
A) Noah left his bicycle outside.
B) Winter lasted for several months.
C) The chain was rusty and the tires were flat.
D) Noah did not have a bike cover.
Leaving the bike out in winter weather is the cause; the damage Noah found is the effect. Cold air leaks tires and snow rusts metal parts over time.
4. Which sentence correctly shows an effect followed by a cause?
A) The ice cream melted because it sat in the sun too long.
B) She was tired so she went to bed.
C) The tree fell down and the sky was blue.
D) Because it was Monday, it was also Tuesday.
When 'because' comes in the middle, the effect is stated first and the cause comes after. The melted ice cream is the effect, and sitting in the hot sun is the cause.
Part B: Fill in the Blank
Write the correct answer on each line.
1. The mayor closed the beach because there were reports of sharks nearby.
Sharks near a beach are a danger to swimmers. The word 'because' shows that the shark sightings are the reason the mayor took action to close the beach.
2. The elevator was broken, so everyone had to take the stairs.
When an elevator stops working, stairs become the only way to move between floors. The word 'so' connects the broken elevator to that result.
3. She read one chapter every night. Therefore, she finished the whole book in two weeks.
'Therefore' begins the second sentence and is followed by a comma. Steady nightly reading added up to a full book over fourteen days.
4. Since the museum was free on Saturdays, the family visited every weekend.
'Since' is capitalized at the beginning of the sentence and gives the reason. Free admission made it easy for the family to make weekly visits.
5. The old bridge was not safe. As a result, the town built a new one.
'As a result' connects an unsafe situation to the action that fixed it. Building a new bridge was the town's response to keep people safe.