Question 216·Medium·Rhetorical Synthesis
While researching a topic, a student has taken the following notes:
• Since the 1970s, about 50 % of the world’s coral reefs have been lost.
• Rising ocean temperatures caused by increased greenhouse gas emissions are the leading driver of coral decline.
• Coral bleaching happens when stressed corals expel the algae that give them color and nutrients.
• Bleached reefs are more susceptible to disease and death.
• Without major emission reductions, scientists project that 90 % of reefs could be threatened by 2050.
The student wants to emphasize the dramatic reduction in coral reefs and identify its main cause. Which choice most effectively uses relevant information from the notes to accomplish these goals?
For rhetorical synthesis questions like this, first restate the task in your own words (what exactly must the sentence do?). Then, scan the notes and underline or mentally tag the specific bullets that match each part of the task (for example, one note for the magnitude of change, one for the main cause). Next, quickly eliminate any answer choices that leave out one of those key elements or introduce extra focus (like future predictions or side details) that distracts from the stated goal. Finally, choose the option that most directly and accurately combines the necessary notes into a single clear sentence, without adding information not supported by the notes.
Hints
Match the question to the notes
Identify which note tells you how much coral has already been lost and which note names the leading driver of coral decline.
Check for both goals in each answer
Ask of each choice: does it both (1) emphasize the scale of past loss and (2) clearly state the main cause of that loss, not just any threat or a future risk?
Watch out for off-target information
Be careful with choices that focus mainly on how bleaching works, predictions about 2050, or a list of various threats; those might be true but not what the student wants to emphasize here.
Step-by-step Explanation
Understand the task
The question states that the student wants to do two things:
- Emphasize the dramatic reduction in coral reefs.
- Identify the main cause of that reduction.
The best answer must clearly do both of these, using information from the notes.
Locate the needed information in the notes
Look through the notes and match them to the two goals.
- Dramatic reduction: The note that says “Since the 1970s, about 50% of the world’s coral reefs have been lost” clearly shows how big the decline is.
- Main cause: The note that says “Rising ocean temperatures caused by increased greenhouse gas emissions are the leading driver of coral decline” identifies the primary cause.
A correct choice should use both of these ideas: large past loss and the leading cause.
Check which choices mention the reduction
Now scan the answer options for any that actually state how much coral has already been lost.
- Some choices talk about what bleaching is or what might happen by 2050, or list several threats, but do not mention the amount already lost.
- Only one choice mentions that about half of the reefs are gone since the 1970s, which is the dramatic reduction from the notes.
Keep that choice in mind as a strong candidate, but still verify that it also correctly states the main cause.
Check which choice gives the main cause and finalize
From the notes, the leading driver of coral decline is rising ocean temperatures caused by increased greenhouse gas emissions, which lead to widespread bleaching.
The only option that both (1) highlights that about half of the world’s coral reefs have disappeared since the 1970s and (2) attributes this mostly to greenhouse-gas-driven ocean warming that triggers bleaching is:
B) Since the 1970s, half of the world's coral reefs have vanished, largely because greenhouse-gas-driven ocean warming triggers widespread bleaching.