Question 85·Easy·Command of Evidence
A student is writing a short report about a marine biology experiment. In the experiment, researchers raised Pacific oyster larvae in seawater with different salinity levels and recorded the average percent of larvae that survived after 48 hours. Referring to the graph, the student wants to support the claim that oyster larvae survive best at a salinity of 30 parts per thousand (ppt), and _____.
Which choice most effectively uses data from the graph to complete the text?
For command-of-evidence questions with graphs, first identify exactly what the sentence is claiming (here, survival at 30 ppt is best and a second, specific data point should support the discussion). Then read the graph carefully for the relevant category and choose the option that reports the same value and units without changing the salinity level or mixing up which bar is highest.
Hints
Use the bar heights
Look at the bars for 20 ppt, 25 ppt, and 35 ppt and note their approximate percent values.
Check the 25 ppt value
Focus on the bar above 25 ppt and see which answer choice reports that same survival percent.
Eliminate mismatches
Cross out any choice that gives a survival percent that does not match the bar height at the stated salinity.
Step-by-step Explanation
Identify what the sentence needs
The blank should be filled with a statement that matches one of the graph’s survival values at a salinity level other than 30 ppt.
Read the relevant bar from the graph
On the graph, the bar for 25 ppt reaches about 70% survival.
Match the statement to the graph
The choice that correctly reports that value is survival at 25 ppt was about 70 percent.