In order to ensure the progress of the construction, he worked hard from down to dusk and finally accomplished with flying colors each task assigned by his superior .
In order to guarantee the construction work not be delayed, I’ve been working hard to solve every problems and excellently faithful to each task assigned by superiors.
我感觉原文意思是不是"出色并忠诚地完成上级交给的各项任务",不过我还是按原文翻译的.