The main pollution reasons include the species hydrogeologic conditions, sewage irrigation, landfill of municipal refuse, and regional groundwater drawdown.

The results show that when increasing the wheel load, drawbar pull accordingly increase and the tractive efficiency show downtrend before uptrend.

随着轮齿高度的增加，挂钩牵引力会随之增大，车轮的最大牵引效率有所降低；

The maximum drawbar pull in earthmoving machinery is the one of main parameters in design and it is limited by the drive slip.

最大牵引力是土方机械设计的主要参数之一，其取决于对土方机械行走系统的滑转率的控制。

When the drive slip is less than 0.05~ 0.30 percent, the drawbar pull in earth-moving machinery is good.

滑转率在0.05～0.30时，可使土方机械的驱动力达到最佳。

Drawbar pull-weight ratio

牵引杆拉力-重量比

The predicting formula of the drawbar pull of driven wheels running on the sand is obtained by model test.

通过模拟试验，得出了驱动轮在砂地上行驶时的挂钩牵引力预测公式。

The increase of lug height may result in the improvement of drawbar pull and driving efficiency.

增加齿高可以提高牵引力和驱动效率。

TESTING Experiment and Analysis on Tractor Drawbar Pull Characteristics

拖拉机牵引性能试验分析

Trailer with adjustable drawbar height

牵引杆高度可调式挂车

The suitcase body is provided with an adjustable drawbar and roller wheels.

箱体设置有可调拉杆和滚轮。

Achievements, Problems and Prospects in China's Water Conservancy Construction

中国水利建设的成就问题和展望

Water Conservancy Construction and Ecological Environment Protection for Sustainable Development

水利工程建设与保护生态环境可持续发展

Chapter IV, this chapter is mainly analyzed on water conservancy construction and land development.

第四章主要论述宁夏平原的水利建设与土地垦殖情况。

Chinese traditional water conservancy construction and development is decided has specific geographical conditions.

在环境史视野下研究发现，中国传统农田水利建设与发展是有特定的地理环境决定的。

On farmland construction of water conservancy works in China

略论我国农田水利基本建设

Policy about developing technical equipment of water conservancy works

发展水利技术装备的政策思考

Research on the Techniques and System for 3D Visual Simulation in Water Conservancy Works

水利工程三维可视化仿真技术与系统研究

Strengthening construction of water conservancy works and rural energy construction;

加强农田水利和农村能源建设；

He required his painters to draw inspiration from nature and grasp both the subject's image and inner world.

他要求画家要师法自然，把握对象的“情态形色”。

When in doubt, draw inspiration from nature as natural tones very rarely clash.

要是觉得不确定，就从大自然中找点灵感，因为自然的颜色很少会不协调。

Are there any analogies you can draw from nature?

从性质上可以得出什么类推法吗？