off-grade的用法和樣例：
詞匯搭配
- cut off grade 品位下限,邊界品位...
- off-grade sponge 不合格海綿金屬,不合...
- off-grade iron 等外鐵,等外生鐵,不...
- off grade metal 等外金屬
- off-grade product (磚的) 等外品...
- cut-off grade 品位下限
- off-grade alumina 不合格氧化鋁,不合格...
- off-grade metal 不合格金屬
- off-grade qualities 等外貨
