Correct or improve the translation of the following English sentences.原文：The production of various electron tubes has been increased four times as against 1958. 译文：各种电子管的产量比1958年增加了四倍。改译：

Correct or improve the translation of the following English sentences.原文：The production of various electron tubes has been increased four times as against 1958. 译文：各种电子管的产量比1958年增加了四倍。改译：

各种电子管的产量比1958年增加了三倍。