Ответ:

1. We were driving to the lake when we saw a rainbow.

2. John shouted for help but no one could hear him.

3. Jane was wondering where Bob was when he suddenly appeared.

4. The sun was shining and the birds were singing while we were walking in the forest.

5. We felt exhausted but happy to be alive.

6. He watched the snow as it fell softly on the trees.