1. Types and structures of ladders: There are many types of ladders, including indoor ladders, outdoor ladders, folding ladders and telescopic ladders. Indoor ladders are usually made of wood, metal or plastic, which are stable in structure and easy to clean. The outdoor ladder is made of metal, which is more durable and can withstand harsh environmental conditions.
2. Use and precautions of ladders: When using ladders, you should pay attention to the following points. First of all, choose a ladder that suits your height and physique, and avoid using a ladder that is too high to cause physical injury. Secondly, check whether the ladder is stable, damaged and aging before use. Watch your step when using a ladder to avoid slipping.
3. Maintenance and maintenance of the ladder: In order to prolong the service life of the ladder, regular maintenance and maintenance are needed. First, check the structure and connection parts of the ladder regularly to ensure its stability and reliability. Secondly, all parts of the ladder should be cleaned and lubricated regularly to make it run flexibly.
Word combinations of ladders
1, Terrace: Terrace refers to the transformation of sloping land into a series of parallel steps, so as to plant crops or improve land utilization. In China, terraced fields are an ancient rice planting method with a long history and mature technology. By building terraced fields, soil erosion can be prevented, water conservation capacity of land can be improved, and crop yield can be increased.
2. Ladder: A ladder is a climbing or descending tool, which usually consists of a series of parallel steps and handrails. Ladders are very common in daily life, such as in houses, office buildings, shopping malls and other buildings, as well as in some special occasions, such as power maintenance and external wall cleaning.
3. Stairs: Stairs refer to a series of parallel steps, which are usually used for walking up and down or entering buildings. Stairs can be fixed or movable, such as escalators. In architectural design, stairs are often an important element, which can increase the layering and aesthetic feeling of space.
4. Trapezoid: Trapezoid is a quadrilateral, in which two sides are parallel and the other two sides are not parallel. Trapezoid is a basic figure in geometry, which can be used in various mathematical operations and graphic design. In real life, trapezoid is also widely used, such as the design of terraces and the modeling of stairs.
5. Echelon: Militarily speaking, echelon refers to troops equipped with personnel and equipment in a certain order. Echelon is an advanced combat grouping method, which can improve the combat capability and mobility of troops. In war, echelon is widely used, such as infantry echelon and tank echelon.