refines

"My car needs gasoline; I'll fill it up before going to school. "

"The students cleared their desks before the math test. "

"The coarseness of the sandpaper made it unsuitable for polishing delicate wood. "

"Even animals in the Jewish system cause impurity only when they are dead."

"The student's vulgarity in class offended many of his classmates. "

"to refine gold"

"The artist preferred to use unmixed paint straight from the tube to achieve a bold, vibrant color. "

"The delicacy of the antique teacup meant we had to handle it with extra care. "

"The student's essay demonstrated excellence in writing. "

"Buying more servers would improve performance."

"The family-owned factory in China handled the export of toys to many countries. "

"The value of testimony depends on its accuracy."