Researcher: Soils are adversely affected by road salts used to melt ice and snow, particularly along roadsides and salt storage areas. Soil samples were collected from highway medians and in salt storage yards. These samples showed chloride levels 11-160 times the level sufficient to inhibit bacteria growth in soil. Inhibited bacterial growth in soil greatly inhibits plant growth in that soil.
An agricultural official would like to use the researcher's result to support the argument that sand, rather than road salts, should be used as a winter road treatment, thereby eliminating the need for salt yards. Select the additional information that, if true, would most strengthen the official's case and select the additional information that, if true, would most weaken the official's case. Make only two selections, one in each column.