在公元前200年左右的中国，他们发现通过在粘土中添加矿物质可以改善陶瓷的外观和强度。

In China at around 200 BC, they discovered that by adding minerals to the clay they could improve both the appearance and the strength of the ceramics.

youdao

“有效使用期”或“最好于该日期前使用”表示的是该产品在这个日期前，从口感、质地、外观、气味和营养价值等各方面保质着最佳质量，过期之后质量就会逐渐下降。

The “use-by” or “best if used-by” date indicates the last day that the item is at its best quality as far as taste, texture, appearance, odor, and nutritional value. The decline after that is gradual.

youdao

“北冰洋”号的船员两天前就发现了这艘配备重型武器的舰只。另外，根据巴尔捷涅夫的介绍，预示着凶多吉少的舰船外观促使他的新伙伴们又一次紧张地打开了伏特加。

The Arctic Sea's crew had spotted the heavily armed vessel two days previously and, according to Bartenev, its ominous appearance prompted his new companions to nervously break out the vodka again.

youdao