Merge pull request #21 from HungTDO/develop

Change build target to APi 16
add DB and Audio for Listening1
add image for listening1
Merge pull request #22 from dinhphamcao/master

Add BD + Media files for Listening 1
edit type of image jpg to png
Merge pull request #23 from dinhphamcao/master

edit type of image jpg to png
Add handle Database for Exam Table