You probably don't think about soil often, but the following report may help you learn about science of soil.

What is soil made of?

Soil is made of sediments (沉积物) and humus(腐殖质). Sediment is small pieces of rock broken down over time by rain, ice, and wind. Sediment is often found in water. Humus comes from decayed(腐烂的) plants and animals. It helps give plants a lot of the food they need to grow.

How does soil form?

Over centuries, rock breaks down into very small pieces.

The rock pieces mix with humus.

The humus gets thicker and thicker over time. Soil is formed(形成)l

How are soils different?

Soils can be different colors and have different textures(质感). Texture is how the surface of an object feels. Color and texture are two features(特征) of soil.

Plants and soil

Plants do not grow well in some soils. Sandy soi1 is too dry. It does not hold water. Soil with too much clay is too thick. Most plants grow well in dark, rich garden soil that has different sediments and a lot of humus in it.

    On June 2, 1886, a German captain threw a message in a bottle into the water while his ship crossed the Indian Ocean. Around 132 years later in January, the bottle was found on the Australian coast{#blank#}1{#/blank#}

    The bottle was thrown into the water to track ocean currents (洋流). Between 1864 and 1933, German sailors threw thousands of bottles into the sea.{#blank#}2{#/blank#}

    But throwing messages in bottles into the ocean is not just for scientists. People send out such messages for many reasons. Some people write information about themselves in the hopes of finding a pen pal{#blank#}3{#/blank#} And still other people just write down some jokes, song lyrics or anything else they think might be fun.

    There are even online messages in bottles. People can send the messages through WeChat or QQ.

    The reasons and ways might be different, but the goal is always the same: to reach out and try to connect with someone{#blank#}4{#/blank#} In 1988, the British band The Police wrote a song called Message in A Bottle that describes this feeling.

    As the song's lyrics say, we are “a hundred billion castaways(被抛弃者) looking for a home”. When will you feel relieved (释然的) ? “A hundred billion bottles washed up on the shore{#blank#}5{#/blank#}

A. Others write down secrets, hoping that the waves will wash them away.

B. This kind of shared feeling might be why this tradition has remained popular for so long.

C. making it the oldest-known message in a bottle in the world.

D. Seems I'm not alone at being alone.

E. Some 663 of those messages were found later.

    My friend Tom is a good student. He is 14 years old. He is 1.53 metres tall. I am a bit short. I'm only 1.45 metres tall. Tom is a good football player. We likes playing football after school. Tom has two long legs and two big feet. His arms are long. His favorite colour is blue. Gina is Tom's sister. She is only 1 year old. She is 0.72 metres tall. She looks beautiful. She has two big eyes and a small mouth. Her favorite colour is pink. Look! She is wearing a pink dress.

    April 22 is Earth Day. Everyone on earth should care about and protect the earth! The earth has warmed by about 1 °F over the past 100 years, but why and how? Well, scientists are not quite sure. Maybe the earth gets warmer and warmer on its own. {#blank#}1{#/blank#}

    First, greenhouse effect(效应) is a very important reason for the change of the earth. People give out too much energy into the air every year. It makes the earth warmer. {#blank#}2{#/blank#} Sometimes it becomes too hot and sometimes too cold. Sometimes there is too much rain and sometimes too little. The change of the climate makes the earth warmer. In turn, the warmth of the earth changes the climate, too.

    When the earth becomes warmer, there may be more rain and a rise in sea level. {#blank#}3{#/blank#} On a Pacific island, 100 people have to move to higher ground because the sea is rising. These people can no longer live on the coast. Before that, two islands without people went underwater in 1999. Scientists say that the seas can rise by nearly one metre by 2100.

People can affect the earth's air, land and water. As for us, we can do many things to protect the earth.{#blank#}4{#/blank#} We can tell more people about protecting the earth.