<正>In accordance with the theory of development economies, developing countries should maintain a current account deficit and capital account surplus,and achie
Vegetation roots contribute to soil fixation and reinforcement, thus improving soil resistance against erosion. Generally, the amount of soil fixation presented
<正>In the middle of last December,the key purchase contracts for coal used in power generation in 2008 were signed,reflecting a demand for more than 1.085 bill