回复：thank you. how about I explain like this

As the budget shows, we have enough to live modestly. I need to work because I want to acquire more working experiences in order to contribute to my long-term career.
-Fine and add "at the same time, more income is alway good to the family".

I declare that the money I earn will be used for cultural, recreational and related travel activities and will not be used to support my J-1 spouse.
-Not need these words.