Answer:
1. Our parents used to be rich before they had my brother and me.
2. I regretted staying up so late last night surfing the net.
3. That's the biggest pizza I've ever seen.
4.Those letters should have been finished ages ago.
5.We should still go for our walk, in spite of the snow.
Step-by-step explanation:
To complete the given sentences using the words given, we can change the word form as required. This means changing the pattern of the words in the original sentence in accordance with the required word to be incorporated into the new sentence.
Therefore, the newly completed sentences using the given words are as below-
1. Our parents used to be rich before they had my brother and me.
2. I regretted staying up so late last night surfing the net.
3. That's the biggest pizza I've ever seen.
4.Those letters should have been finished ages ago.
5.We should still go for our walk, in spite of the snow.