( )When you come here,you may have some problems _ many things.
A.with B.about C.on D.in
( )Nicole always _ happy childhood when she feels sad.
A.thinks over B.thinks to C.thinks with D.think of
( )_ he is,_he feels.
A.the busier,the happy B.the busy,the happy C.the busier,the happier
D.the busier,the happiest