雅思优秀作文范文

The diagram shows the life cycle of silkworms and the process of making silk cloth.

The life cycle is divided into several particular developing stages. It starts when a moth produces her eggs on the mulberry leaves. After ten days the eggs grow into silkworm larva, whose foods are the mulberry leaf. The second stage ends. In the following four to six weeks, the larva will generate silk threats which cover the larva. This is the third stage. The fourth stage lasts for three or eight days during which cocoon is formed. 16 days after the formation of the cocoon, a moth finally comes out of the cocoon. A new cycle starts.

The production of the silk cloth consists of numerous steps. The first is to select cocoons, which then are heated in boiled water. After the heat treatment, the cocoon is ready to be decomposed into threads ranging from 300 to 900 meters in length. The second is to twist the thread together. To dye is the third. After this process, silk cloth is woven.