In this article, the center conditions, isochronous center conditions and bifurcation of limit cycles at infinity for a class of fifth system are investigated.是什么意思_In this article, the center conditions, isochronous center conditions and bifurcation of limit cycles at infinity for a class of fifth system are investigated.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句