阅读下列短文，从每题所给的四个选项(A、B、C、D)中，选出最佳选项。

A

At first, the earth’s surface layer (层 ) was made up of huge blocks of hard, solid rocks. There slowly, the rocks broke up into smaller and smaller pieces. Finally stones, pebble(卵石) and grains of sand were formed. Many sorts of plants and animals lived and died on the surface of the earth. They remain mixed up with the stones, pebbles and formed soil. The outmost layer of the earth is soil.

There are many ways in which large pieces of rock break into smaller ones. Wind, water, heat and cold help to break up rocks. When winds blow grains of sand against a large rock for a long time, the softer layer of the rock are slowly worn away. These leave holes and crack(裂缝) in the rock, which become bigger and finally the rock breaks up into smaller pieces.

The moving water of streams and rivers also help to break up rocks. As the water moves along, it carries with it small pieces of rock. These rub the larger ones. Thus, the larger rocks are worn down to smaller pieces.

The heat of the sun also help to breaking up rocks. When the sun shines, the rocks become very hot. If these rocks are suddenly cooled, they may crack. Ice also plays a part in making soil. Water in the cracks can turn into ice in cold weather. As this happens, it becomes bigger and cracks become wider, and finally break into smaller pieces.

1.According to the passage, soil__

A.forms very slowly B.is a mixture of stones, pebbles and sand etc

C.makes up the layers of the earth D.is becoming smaller and smaller

2.Which of the following speeds up the break of rocks most?

A.Hot weather. B.Cold water.

C.Sharp changes in temperature. D.More dead plants in the cracks.

3. What does the underlined word in Paragraph One mean?

A the first layer of the surface B the furthest layer

C .the middle layer D the thinnest layer

4.Which of the following is NOT true?

A.The remains of many plants of animals formed soil.

B.If a large rock never moves, it will never break up.

C.Even if a large rock never moves, it will break up.

D.Ice in the cracks helps to break up rocks,

5.The best title for this passage should be ___ .

A.Soil from Rocks B.Ways to Break up Rocks

C.Soil on die Earth D.Soil, Outmost Layer of the Earth