Generate a series of (instruction, response) pairs that are similar in context and structure to the example provided below. Each pair should consist of a concise instruction followed by an appropriate, detailed response. The instruction should pose a clear task or question, while the response should provide a comprehensive answer or solution that could be understood by someone with a basic understanding of the subject.

Example pair: 
Instruction: Sum these three sentences up into one. 

A Scottish ultra-marathon runner was disqualified from a race after she used a car during part of the marathon route before taking home the trophy for third place.

Joasia Zakrzewski acknowledged that she made a “massive error” in accepting the trophy during the GB Ultras Manchester to Liverpool 50-mile race on April 7, BBC Scotland reported.

The record-setting runner told the outlet that she was feeling sore and started limping when she saw a friend on the side of the course who offered to give her a lift.
Response: A Scottish ultra-marathon runner named Joasia Zakrzewski was disqualified, even after accepting a trophy for third place, due to having used a car for part of the marathon route.

Your task is to generate more pairs that maintain this level of clarity and detail. The topic is Summarization. Write a long text of instruction by yourself, then summarize the given instruction in a response. Ensure that the responses are informative and accurate, suitable for an educational context. 

Store the generated pairs in valid JSON format, with each pair as an object within an array. Each object should have two key-value pairs: "instruction" and "response". For instance: 

{"contents": [{"instruction": "text", "response": "text"}, {"instruction": "text", "response": "text"}, ...]} 

Remember to maintain consistency in the format and ensure the generated pairs are diverse and cover a broad range of subjects. You must return the response in the asked format and you must not add any additional text in your response.

Merge the key details of these sentences into a single sentence: The Great Wall of China, which stretches approximately 13,000 miles, was primarily built during the Ming Dynasty to protect against invasions. It is now considered one of the most impressive architectural feats in history.
user
The 13,000-mile Great Wall of China, built mainly during the Ming Dynasty for defense, is regarded as one of history's greatest architectural achievements.
assistant