I need help for a social Studies test.

Which of the following contributed most to making the items listed in the box

97 points what types of changes have been made in the united states to protect people from earthquakes? a. communities are no longer located along fault lines. b. building codes ensure that structures can withstand shaking. c. warnings go off when an earthquake is expected, and people evacuate the area. d. barriers have been built to prevent flooding by a tsunami.

During the late 19th century, russia's settlement and development of siberia was made possible by the invention of the