Short sentences about children playing in the sand

Short sentences about children playing in the sand are as follows:

1. In our free time after get off work, we take our children to play in the sand, and play with our children to feel our innocent happiness. What a blessing!

2. The children had fun playing in the sand and told me that the incredibly beautiful circle is also the only way to the mountainous countryside from the outside world.

3. Talk about the children playing in the sand, reliving the happy times, just like this for a few years. < /p>

5. Today, I walked with my children on the warm beach. I saw seagulls flying by, an arc, and small fish swimming in the water. At this time, the beautiful scenery grew together.

6. The children ran to the beach happily, their smiles brighter than the sun in the sky;

7. The seaside is a beach, and the beach is full of various colors. Various patterns of shells. The children here have seen so much that they ignore these shells, and the shells have to lie there lonely.

Expand knowledge - sand:

The most common component of sand is silica, usually in the form of quartz, which is chemically stable and hard enough to resist weathering.

The main component of sand is silica (SiO2), and the density of silica is 2.65g/cm^3, that is, 2.65t/m^3. Sand is made up of minerals and tiny rock fragments. Rock fragments are formed by erosion and weathering of rocks. The composition of sand varies from place to place, depending on the source and conditions of local rocks

Sand is generally divided into two categories: natural sand and artificial sand. Rock particles with a particle size of less than 5 mm formed by natural conditions (mainly rock weathering) are called natural sand. Artificial sand is made from crushed rocks. It is generally not used due to its high cost and the abundance of flakes and powder.

According to its origin, natural sand can be divided into river sand, sea sand and mountain sand. The surface of mountain sand is rough, the particles are angular, the sand content is high, the content of organic impurities is high, and the quality is poor. Sea sand and river sand have smooth surfaces, but sea sand has a high salt content, which has a certain impact on concrete and mortar. River sand is relatively clean and widely used.

The thickness of sand refers to the average thickness of sand particles of different sizes mixed together. Usually there are coarse sand, medium sand and fine sand. The particle gradation of sand refers to the proportion of sand size particles.

If the sand is of the same thickness, the voids are the largest. When sand of two particle sizes is matched, the voids are reduced. When sand of three particle sizes is matched, the voids are even smaller. It can be seen that the porosity of sand depends on the matching degree of particle sizes of sand materials at all levels.

Well-graded sand can not only save cement, but also improve the compactness and strength of concrete and mortar. The thickness of sand is expressed by the fineness modulus Mx. The larger the fineness modulus, the coarser the sand. According to the range of fineness modulus, sand is divided into coarse sand, medium sand, fine sand and extra fine sand.