Thanks a lot for your thoughtful comment again. True, it's possible that the spillover from bats to humans occurred by aerosol transmission. (After all, I doubt bats sneeze since they don't get sick from the coronaviruses they carry.) But I think it's still important to find the SARS-CoV-2 progenitor with about 99% genomic identity overlap in bats, as scientists did with MERS-CoV and SARS-CoV-1. Still, as you have pointed out, even if scientists found the progenitor, we only know where the spillover occurred but not when.