Turn the underlined part of the sentence into a participle clause (present, past or present perfect participle}.
Example: We are lying in the sun and we are enjoying life. → Lying in the sun, we are enjoying life.
The boy had brushed his teeth. He was allowed to watch a few more minutes of television. → Ответ
his teeth, the boy was allowed to watch a few more minutes of television.
The children were sitting on their beds and watched the thunderstorm. → The children were sitting on their beds Ответ
the thunderstorm.
They were surprised by a sudden storm and had to seek shelter under a tree. → Ответ
by a sudden storm, they had to seek shelter under a tree.
When they had found the secret island, they started searching for the treasure.→ Ответ
the secret island, they started searching for the treasure.

Having brushed his teeth, the boy was allowed to watch a few more minutes of television. The children were sitting on their beds watching the thunderstorm. Surprised by a sudden storm, they had to seek shelter under a tree. Having found the secret island, they started searching for the treasure.