For each of the following, find a word that may be appended to each of the three words in the group to form three new valid words.
For example, given: “friend, owner, dealer”, you would need to find the word “ship”, which, when appended to these words, results in the three new valid words: “friendship”, “ownership”, and “dealership” respectively.
1. water, air, space
2. back, off, multi
3. car, white, hand
4. cow, dumb, door