add A.3-10

add A.3-10
add A.3-9

add A.3-9
add A.3-8

add A.3-8
add A.3-5

add A.3-5
add A.3-6

add A.3-6
add A.3-2

add A.3-2
Merge branch 'master' of https://github.com/CocoaChina-editors/Welcome-to-Swift