The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity -LRB- sericulture -RRB- .
In history , silk came from China and was very expensive .
In history , silk came from China and was very expensive .
文を簡略化してください: The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity -LRB- sericulture -RRB- . 出力: