merge
Merge branch 'master' of https://github.com/LitusProject/Litus
Merge branch 'master' of https://github.com/LitusProject/Litus
Merge branch 'master' of https://github.com/LitusProject/Litus
fixed quizbug
Merge branch 'master' of https://github.com/LitusProject/Litus