The window of opportunity to uncover the true origins of Covid is closing and could soon be 'biologically impossible', a report has warned. World Health Organization experts sent to China to learn of how the pandemic began say studies probing most likely theories 'have stalled'. The team say vital research would require looking for traces of the virus in blood samples from some of the original patients and in animals, which wane over time. The communist Government in China has stymied all efforts for independent investigations into how the virus first jumped to humans in epicentre Wuhan. In their report...