自由人不能发球，当球高于球网时不能扣球，也不能按轮转顺序站到前排去，但他在接对方发球和后排防守方面却起到了至关重要的作用。

The libero cannot serve, spike the ball over the net or rotate into the front-line positions, but plays a vital role for the team in serve reception and backcourt defense.

youdao

自由人不能发球，当球高于球网时不能扣球，也不能按轮转顺序站到前排去，但他在接对方发球和后排防守方面却起到了至关重要的作用。

The libero cannot serve, spike the ball over the net or rotate into the front-line positions, but plays a vital role for the team in serve reception and backcourt defense.

youdao