2016届高考英语二轮专题总复习精选综合能力专练：完形填空8_高考复习指南

2016届高考英语二轮专题总复习精选综合能力专练：完形填空8

　　12．D。固定结构make use of意思为“利用”。

　　13．C。in the future意思为“将来”，为正确选项。而in future意思为“今后”，不合文意。

　　14．C。根据上下文，电脑是不可能取代人类的，而人类应永远是电脑的操纵者，故选always。

　　15．A。固定结构with the help of意思为“在……的帮助下”。

　　Have you ever noticed the colour of the water in a river or stream after a heavy rainfall? What do you think caused this change in colour? It is soil that has been washed into the river from the riverbank or from the nearby fields.

　　Components of Soil

　　Soil is made up of a number of layers (层) , each having its own distinctive colour and texture. The upper layer is known as the litter. It acts like a blanket，limiting temperature changes and reducing water loss. The topsoil layer is made up of small particles of rock mixed with rotten plant and animal matter called humus (腐殖质), which is black and gives the topsoil its dark colour. This layer is usually rich in nutrients, oxygen, and water. Below the topsoil is the subsoil, a layer that contains more stones mixed with only small amounts of organic matter. This layer is lighter in colour because of the lack of humus. Beneath the soil lies a layer of bedrock.

　　Soil forms from the bottom up. Over time bedrock is attacked by rain, wind, frost, and snow. It is gradually broken down into smaller particles in a process called weathering. Plants begin to grow，and rotten materials enrich the topsoil. Most of the soil in Eastern Canada ，for example ，was formed from weathered rock that was exposed when the ice disappeared 12,000 years ago.