Lời giải chi tiết:

1. Mark went on working although he felt unwell.

• Chuyển thành: Mark went on working in spite of feeling unwell.

1. I enjoyed the film although the story was silly.

• Chuyển thành: I enjoyed the film in spite of the silly story.

1. Because of the heavy rain, the place is flooded.

• Đã đúng cấu trúc.

1. There was a car crash last night because the road was slippery.

• Chuyển thành: There was a car crash last night because of the slippery road.

1. The children were swimming for hours because the water was cold.

• Chuyển thành: The children were swimming for hours in spite of the cold water.
• Lưu ý: Câu này có thể chuyển đổi theo cả hai cách, tùy thuộc vào ngữ cảnh muốn nhấn mạnh. Nếu muốn nhấn mạnh việc trẻ em bơi trong thời tiết lạnh thì dùng "in spite of", còn nếu muốn nhấn mạnh nguyên nhân khiến chúng bơi thì dùng "because of".

1. We went out in spite of the heavy rain.

• Chuyển thành: Although it was raining heavily, we went out.

1. Rice grows well here because of the warm and wet weather.

• Đã đúng cấu trúc.

1. She didn't go to school because she was seriously ill.

• Chuyển thành: She didn't go to school because of her serious illness.

1. It rained heavily but he went to class in time.

• Chuyển thành: Although it rained heavily, he went to class in time.
• Lưu ý: Ở đây, "but" cũng có nghĩa tương đương với "although".

1. It is raining, so we stay at home.

• Chuyển thành: Because it is raining, we stay at home.
• Lưu ý: "So" dùng để chỉ kết quả, trong khi "because" chỉ nguyên nhân.

1. Tomorrow is a public holiday, so all the shops will be shut.

• Đã đúng cấu trúc.

1. Although he was old, he runs 4 miles before breakfast.

• Chuyển thành: In spite of his old age, he runs 4 miles before breakfast.