Once plentiful in the river the sturgeon population had dropped below 40000 and scientists were unable to explain the die-offs of mostly female fish.是什么意思_Once plentiful in the river the sturgeon population had dropped below 40000 and scientists were unable to explain the die-offs of mostly female fish.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句