The teacher who sang beautifully in our last spring festival is from England.

• Error: "beautifulin" should be "beautifully."
• Correction: B. beautiful → beautifully

The discovery of gold in California in 1848 led to the Gold Rush.

• Error: "on" should be "in."
• Correction: A. on → in

I love this small village where I used to live for six years in my childhood.

• Error: "which" should be "where."
• Correction: B. which → where

The fish in the lake in the city centre have died because of the polluted water.

• Error: "in the city" should come after "the lake" for clarity.
• Correction: B. in the city → (no change needed)

• 5. The teacher who sang beautifully in our last spring festival is from England.

• The discovery of gold in California in 1848 led to the Gold Rush.
• I love this small village where I used to live for six years in my childhood.
• The fish in the lake in the city centre have died because of the polluted water.