保护作物

As people settled permanently along the Fertile Crescent, they built irrigation systems to bring water to crops and constructed levees as protection against the flooding rivers.

当人们解决沿新月永久，他们修建灌溉系统，将水和作物对保护河流洪水建造堤坝。

Do not gum up the work by telling mother what we are going to do .

别告诉母亲我们要干的事，那会把事情搞糟的。

In recent years, application of the partial prestressed concrete beam s is developed.

近年来，随着部分预应力砼梁应用的推广，发现我国规范所采用的名义拉应力法的计算结果不稳定。