Which of the following technological advances played an important role in opening the Great Plains in the late nineteenth century?"(SSUSH 12b) Scientific development of synthetic pesticides Advance irrigation techniques Corporate development of drought-resistant grains Steel plows barbed wire and the mechanical reaper

## Step 1<br />The question is asking about the technological advances that played a significant role in opening the Great Plains in the late nineteenth century. The options provided are: Scientific development of synthetic pesticides, Advance irrigation techniques, Corporate development of drought-resistant grains, and Steel plows, barbed wire, and the mechanical reaper.<br /><br />## Step 2<br />The Great Plains is a vast area of flat land, much of it covered in prairie, steppe, and grassland, which was not conducive to farming before the advent of certain technologies.<br /><br />## Step 3<br />The technological advances that played a significant role in opening the Great Plains in the late nineteenth century were the steel plow, barbed wire, and the mechanical reaper. These technologies made farming possible in the Great Plains.<br /><br />## Step 4<br />The steel plow was invented by John Deere and it was able to cut through the tough prairie soil. Barbed wire was used to fence in the land and the mechanical reaper was used to harvest the crops.