what is the importnce of using different varieties or grow different crop species with resistance to many diseases?

According to anthony platt, author of the child savers: the invention of delinquency, the progressives were not children, but denying them what?

What statement is true about all chemical changes? a) chemical changes can be undone. b) chemical changes cannot be reversed. c) chemical changes change the color of objects. eliminate d) chemical changes do not form new products.

The color contrast between the open ocean and the lagoon between the spit and the mainland. the greater concentration of suspended sediments in the lagoon gives the waters a more turbid appearance. the source of sediment in the lagoon is (are) [(rivers and streams from the mainland) (wind-borne sediment from the spit) (ocean waves washing over the spit) (all of these contribute)].