grade的例句

The boy first showed promise as an athlete in grade school.

这个男孩在上小学的时候就初次显示出成为运动员的潜力。

It was actually used for enriching uranium to weapons-grade levels.

实际上，它是用来将铀浓缩以制造武器。

This grade of wool can be sold at a fairly low price.

这种等级的羊毛只能以相当低的价格卖出。