2015年考研英语作文素材精选十一_大学英语写作

2015年考研英语作文素材精选十一

　　In the Weddell Sea Antarctica, the densest water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.

　　NOTE：

　　salinity / sэlinэti; sэ`linэti/

　　n [U] the high salinity of sea water 海水的高含盐量.

　　---saline / seilain; US -li:n; `selin/

　　1.adj [attrib 作定语] containing salt; salty 含盐的; 咸的:

　　a saline lake 盐湖 saline springs 盐泉

　　saline solution, eg as used for gargling, storing contact lenses, etc 盐溶液.

　　2. n [U] solution of salt and water 盐水.

　　40 Cohesion-tension Theory

　　Atmospheric pressure can support a column of water up to 10 meters high. But plants can move water much higher; the sequoia tree can pump water to its very top more than 100 meters above the ground. Until the end of the nineteenth century, the movement of water in trees and other tall plants was a mystery. Some botanists hypothesized that the living cells of plants acted as pumps. But many experiments demonstrated that the stems of plants in which all the cells are killed can still move water to appreciable heights. Other explanations for the movement of water in plants have been based on root pressure, a push on the water from the roots at the bottom of the plant. But root pressure is not nearly great enough to push water to the tops of tall trees. Furthermore, the conifers, which are among the tallest trees, have unusually low root pressures.