Explain causality: It means explaining the causal relationship among certain facts. Which of the following are not to explain cause and effect? ['Since Xiaoqiu has so deep feelings in her song, how can Xiaoli not hear her?', 'The development of physics has enabled people to study celestial bodies using methods such as spectral analysis and photometry.', "Xiao Wu didn't achieve much because he was too proud.", 'A serious illness forced Lao Zhang to leave his beloved job early.']