This is an interesting question, because the farmer brought three things: a cat, a chicken and a bag of rice, while the cat will eat the chicken and the chicken will eat the rice. So it is necessary to separate the cat from the chicken and the chicken from the rice.

The method is as follows:

① Take the chicken across the bridge first, put it down and then return.

② Bring rice across the bridge, and then bring the chicken back.

③ Put down the chicken and take the cat across the bridge.

Put the cat down and come back with the chicken.

This can prevent cats from eating chickens and chickens from eating rice.

wood bridge

Early wooden bridges were mostly beam bridges, such as the Wei Qiao built on the Weihe River in the Qin Dynasty, which was a multi-span beam bridge. The span of wooden beam bridge is not large, and the span of wooden bridge with legs can be increased. In the 3rd century A.D., China built an outboard wooden bridge with "One Happy and Fifth Step" at the junction of Anxi, Gansu and Turpan, Xinjiang. From 405 to 4 18, a cantilever wooden bridge was built near Linxia, Gansu, with a river width of 40 feet and a bridge height of 50 feet.

The span of splayed wooden bridges and arched wooden bridges can also be increased. /kloc-Bassano Bridge in the 6th century was a splayed wooden bridge.