Answer:
The Last one
Explanation:
an interesting opener, context for the topic, list of materials,steps in the process.
Solar flares *were* the <span>cause of the difficulty, and new instruments *are* the solution.</span>
It says 'evidence' so I'm going to say statistic...
The answer is c.
hope this answer helps ♥
Answer is in the file below
tinyurl.com/wpazsebu
