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Taxes (Details) - Schedule of effective tax rate
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Schedule of effective tax rate [Abstract]      
PRC statutory rates 25.00% 25.00% 25.00%
Preferential tax rates (25.00%) (16.90%) (9.90%)
R&D credits 1.70% (3.40%) (4.00%)
Change in valuation allowance and others (1.30%) (2.80%) 1.60%
Effective tax rate 0.40% 1.90% 2.70%