_____________________ we learn from our mistakes, we can improve.

The phrase "As long as we learn from our mistakes, we can improve" emphasizes a conditional relationship where learning from mistakes is a necessary prerequisite for improvement. By using "as long as," the sentence conveys that the act of learning from mistakes is critical and ensures that improvement is possible. This reflects a positive and encouraging perspective, suggesting that as long as one is willing to learn and grow, progress is achievable.

The other choices do not fit the context as seamlessly. "If only" implies a wishful thinking scenario, which doesn't establish a clear connection to improvement. "Unless" suggests that something will not happen without a specific condition being met, which does not align with the idea of enabling improvement based on learning. "Even if" introduces a sense of uncertainty or concession that does not align with the optimistic tone of the statement about learning leading to improvement. Thus, "as long as" is the best choice as it captures the essence of the statement effectively.