研究人员表示，这种声音一层叠着一层，像二重唱似的。

Researchers say the calls become layered atop one another, almost like a duet.

youdao

研究人员表示，这种声音一层叠着一层，像二重唱似的。

Researchers say the calls become layered atop one another, almost like a duet.

youdao