The difference between them is the Pure Sine Wave inverter produces a better and cleaner current. They are also considerably more expensive. You might find it practical to get a small Pure Sine Wave inverter for any special need you may have, and also a larger Modified Sine Wave inverter for the rest of your applications.
Elm Trees can live over 100 years in their natural environment.
Xanthogaleruca luteola is a serious pest of the elm. Both the adults and larvae feed on the emergent leaves of the elm. Repeated heavy infestation rarely kills the tree outright but weakens it, rendering it vulnerable to disease.