4.12 Security:
various security settings like screen lock, displayed or hidden passwords, etc.
Unknown sources: Click "Unknown sources" and followed by "OK" to allow installation of
unknown origin applications (applications not certified by Google, which does not mean they are
not reliable sources)
4.13 Language and Keyboard: Change the language to use the Tablet, set the automatic spell
correction, keyboard type, etc.
Select Language: 54 languages are available
Remark: Android system can support 54 kind of language, now main interface just support
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