【文章內(nèi)容簡介】
his preserved only the outside.Later they may have pickled their meat by soaking it in salt water.
In hot,dry lands,men found that they could eat meat that had dried while it was still on the bones.They later learned to cut meat into thin strips and hang it up to dry in the hot air.
Men in cold climates found that frozen meat did not spoil.They could leave their meat outside and eat it when they pleased.
『英語知識小品:幫助改良土壤的蚯蚓』 Earthworms that Help Improve the Soil
The earthworm is a useful animal.Out of the ground,it is food for other animals.In the ground,it makes rich soil for fields and gardens.
Earthworms dig tunnels that loosen the soil and make it easy for air and water to reach the roots of plants.These tunnels help keep the soil well drained.
Earthworms drag dead leaves,grass,and flowers into their burrows.When this plant material decays,it makes the soil more fertile.
No other animal is so useful in building up good topsoil.It i