那位杂技演员表演了令人惊叹的里斯利技巧，躺在地上用脚同时抛接三个球。

The acrobat amazed the audience with his ___Risley skills, juggling three balls with his feet while lying down.

这位杂技演员正在表演高难度的Risley技巧。

The acrobat is performing a difficult ___Risley maneuver.