Answer:
people use a variety of keyword phrases
Step-by-step explanation:
Using Exact match is very necessary to avoid unnecessary and irrelevant keywords search query report. If not, the ads are going to come up in the pages where the target consumers do not visit. It is also important to have a good knowledge of keywords searchers are likely to use. If not, there will be mismatches.
When variety of key words are used, there would be difficulties as exact match searches may cause the loss of a potential searcher as they are not using the exact match words