In the experiment, they first learned that black clothes pins could be exchanged for food, while orange ones were worthless.

在实验中，他们首先了解到，黑色的衣夹可以换取食物，而橙色的则一文不值。

The grass was short and green, and there were clothes—props cut from bracken stems, with lines of plaited rushes, and a heap of tiny clothes pins—but no pocket-handkerchiefs!

草又短又绿， 还有衣服——从蕨菜茎上剪下来的道具， 一排排编织的灯芯草， 还有一堆小衣夹——但没有手帕！