Louie bent down and put his hand into the fine-grained sand at his feet.

路易弯下腰，把一只手放入脚下面的细沙中。

youdao

The sand will be severely shaken and sieved to make sure only fine-grained material, less than the width of a human hair in diameter, reaches the instruments.

BBC: Nasa's Curiosity Mars rover to scoop sand sample