Assume you are a quantitative researcher tasked with building a pairs trading strategy in the China A-share market. Walk me through how you would design, implement, and evaluate this strategy from scratch. Specifically, address how you would select appropriate trading pairs, generate trading signals, manage risk, and effectively backtest and optimize the strategy to ensure its robustness and profitability.

假设你是一位量化研究员，任务是在中国A股市场构建一个配对交易策略。请详细描述你将如何从头开始设计、实现和评估这个策略。具体来说，你需要阐述如何选择合适的交易对、如何生成交易信号、如何进行风险管理、以及如何有效地进行回测与优化，以确保策略的稳健性和盈利能力。