Paulsville and Longtown cannot both be included in the candidate' s itinerary of campaign stops  The candidate will make a stop in Paulsville unless Salisbury is made part of the itinerary  Unfortunately, a stop in Salisbury is out of the question
Clearly, then, a stop in Longtown can be ruled out
In agricultural pest control, either pesticides or the introduction of natural enemies of the pest, but not both, will work. Of course, neither will be needed if pest-resistant crops are planted. So if pesticides are in fact needed, it must be that there are no natural enemies of the pest.