poorly graded meaning in English

不良级配的
不良配的
分级不良的
分级差的；分选差的
级配不良的

2 identify the soil as a poorly graded gravel , gp , or as a poorly graded , sand , sp , if it consists predominantly of one size ( uniformly graded ) , or it has a wide range of sizes with some intermediate sizes obviously missing ( gap or skip graded )
2如果土包含一个主要的粒径(均匀的级配) ,或者有一个很宽的,一些中间粒径明显缺失的范围(间隙或跳跃的级配)