allusion|allusions

她演讲中对环保问题的暗示只有少数听众注意到了。

Only a few listeners caught her ___allusion to environmental issues in the speech.

他的演讲中暗藏了许多对古希腊神话的隐喻。

His speech was full of clever ___allusions to ancient Greek mythology.

他在演讲中简短提到了那部经典电影，但没有深入讨论。

He made a brief ___allusion to the classic movie in his speech without going into details.