我爷爷收藏了一枚南非克鲁格金币作为长期投资。

My grandfather keeps a ___Krugerrand as a long-term investment.

克鲁格金币作为南非黄金开采业的象征，常被投资者收藏。

The ___Krugerrand is often collected by investors as a symbol of South Africa's gold mining industry.