[填空题]
An ancient wooden club is fou . h*d3)ib-gr/u5esbjbs07 ( calah fknd that contains 290 g of carbon and has an acti0(75odpzw(d mahx l 9m9e2- uyz(rfb bvity of 8.0 decmz9lb(b0(9(o7wdp5mhed 2 xrfzau-yays per second. Determine its age assuming that in living trees the ratio of $_{6}^{14}\text{C}$ to $_{6}^{12}\text{C}$ atoms is about $1.3 \times 10^{-12}$. t = $\times 10^{4}\ \text{yr}$
