You will need to install a user script manager extension to install this script.
Tested in the following:
Firefox 35.0.1 and Chrome 39.0.2171.95 (64-bit), Linux Mint 17.1 Cinnamon 64-bit
Firefox 35.0.1 and Chrome 40.0.2214.115 m, Windows 8.1 64-bit
Applies to Reviews and Lesson Quiz questions.
Change var strLang = "en"; to var strLang = "ja"; for Japanese questions.