I have a 10-year multaple entry visa to China. Is my 10-year visa still valid?

My mother is dying. I am American Citizen now and I need to go back to China urgently.

Is my 10-year visa to China valid?
Where is the Chinese Los Angeles Consulate authorized Covin-19 test center. Do I need to have 48 hour test before boarding to the airplane? the address of the test center in LA please.