文档介绍：一
The diagrams below show the stages and equipment used in the cement-making process, and how cement is used to produce concrete for building purposes.
Summarise the information by selecting and reporting the main features, and parsons where releant.
The first diagram indicates the stages and equipment in the process of making cement, and the second one illustrates how cement and other materials are mixed to produce concrete for building purposes.
Cement production involves the following steps. The first step is to put limestone and clay on two different conveyors. Then, these two types of materials are pressed into the crusher which breaks them into powder.  After that, the powder is poured into a mixer, and then mixtures are transmitted into a rotating heater which works with heat. The following step is that a band carrier leads the heated powder to a grinder where the es out. Finally, cement is packed into bags,and the process is finished.
Concrete production is much more simple. Four different kinds of materials are needed in different proportion. Gravel accounts for the largest part, at 50%, followed by sand, which is 25%. Cement and water contributes 15% and 10% respectively. The four materials are then mixed and poured into a concrete mixer and after a period of whirling, concrete is produced.
In conclusion, making cement has plex process than making concrete though concrete needs more materials than cement.
二
The diagrams below show the life cycle of the silkworm and the stages in the production of silk cloth.
Summarise the information by selecting and reporting the main features, and parisons where relevant.
The first diagram shows that there are four main stages in the life of the silkworm. First of all, eggs are produced by the moth and it takes ten days for each egg to e a silkworm larva that feeds on mulberry leaves. This stage lasts for up to six weeks until the larva produces a cocoon of silk thread around itself. After a period of about thr