Original sentences:
Gray squirrels are tree squirrels. They love trees, though you often see them on the ground.
Look at the following sentences and find what has changed. What is the effect of the change:
1. Gray squirrels are tree squirrels. They love trees, although you often see them on the ground.
2. Gray squirrels are tree squirrels. It love trees, though you often see them on the ground.
3. Gray squirrels are tree squirrels. They love trees, though you often see they on the ground.