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. war, hem, pad
2. bar, hand, brides
3. pro, con, dif
4. pole, house, cop