The modified 4-step method is structured as follows: 1. Identify the problem or goal: Clearly define the issue or objective that needs to be addressed. 2. Generate potential solutions: Brainstorm and come up with multiple possible ways to solve the problem or achieve the goal. 3. Evaluate and choose the best solution: Assess the potential solutions based on their feasibility, effectiveness, and potential impact, and then select the most suitable one. 4. Implement and monitor the solution: Put the chosen solution into action and closely monitor its progress to ensure it is achieving the desired results. **

The elongation step between 3 and 4 mm is 1 mm. This means that the distance between the two points increases by 1 mm. In terms of percentage, the elongation step represents a 33.3% increase from 3 to 4 mm. This step is significant in terms of measuring and understanding the change in distance or size between the two points. **

The leather sofa may look unattractive after just under 4 years due to wear and tear. Over time, the leather can become faded, scratched, or cracked, especially with regular use. Factors such as exposure to sunlight, spills, and improper maintenance can also contribute to the deterioration of the sofa's appearance. Additionally, the quality of the leather and construction of the sofa can impact how it ages over time. **

The leather sofa may look unattractive after barely 4 years due to a combination of factors such as wear and tear, exposure to sunlight, and lack of proper maintenance. Over time, the leather may become worn, cracked, or discolored, especially if it is not regularly cleaned and conditioned. Additionally, exposure to sunlight can cause the leather to fade and lose its luster. Without proper care and maintenance, a leather sofa can quickly lose its attractive appearance. **

The calorie expenditure for road cycling and mountain biking can vary based on factors such as intensity, terrain, and duration. Generally, road cycling on flat terrain at a moderate pace can burn around 400-600 calories per hour, while mountain biking on varied terrain with hills and obstacles can burn around 500-800 calories per hour. The higher calorie expenditure in mountain biking is due to the increased effort required to navigate the challenging terrain and obstacles. Overall, mountain biking tends to result in a higher calorie expenditure compared to road cycling. **

I'm sorry, but I cannot provide the specific Spanish vocabulary for Unit 4 Step 2 as it may vary depending on the educational curriculum or program you are referring to. I recommend checking your textbook, class notes, or online resources specific to your course for the accurate vocabulary list. If you have any specific words or phrases you would like to know in Spanish, feel free to ask, and I'd be happy to help translate them for you. **

The step-by-step calculation is performed by breaking down a complex problem into smaller, more manageable steps. Each step is carefully executed, and the result is used as the input for the next step. This process continues until the final solution is reached. It helps to ensure accuracy and allows for easy identification of any errors that may occur during the calculation. Additionally, it provides a clear and organized approach to solving the problem. **

Step-by-step calculation involves breaking down a complex problem or equation into smaller, more manageable steps. Each step is carefully executed, with the result of one step becoming the input for the next step. This method helps ensure accuracy and allows for easier identification of errors if they occur. By following a systematic approach, the final solution can be reached efficiently and with confidence. **