It used in straitness field, soft earth layer and instability aquiclude.

主要适用于场地狭窄、软弱土层和不稳定含水土层中的施工。

Ureter straitness, contortion and stone transferring are of important factors influencing on operation outcome.

输尿管狭窄、扭曲、术中出现结石移位是影响手术结果的重要因素。

In present day, straitness of germplasm resource stands the way of maize breeding in China. So, new germplasm and expanding use of germplasm resource arc required.

在当前，玉米种质资源狭窄是我国玉米育种的突出问题，这要求必须补充新的种质，扩大种质资源的利用。