Those in the control group not only didn't see a grade increase, they had lower grades than the grading before the study began.
对照组的学生不仅成绩没有提高，而且比研究开始前的成绩还要低。
2
This unit group includes excavating, grading, paving, drilling and blasting contractors who own and operate their own business.
本单元组包括拥有和经营自己生意的挖掘，分级，铺路，钻井和爆破承建商。
3
Recommendations were graded using methods adapted from the us Preventive Services Task Force and the Grading of Recommendations, Assessment, Development, and Evaluation Working Group.