we are going fishing（ ）next sunday .A on B \

we are going fishing（ ）next sunday .A on B \
we are going fishing（ ）next sunday .
A on B \

we are going fishing（ ）next sunday .A on B \
下个星期..下个月..明年..
前面都不用介词...
直接是..next+week..month..year..
所以选B..不填介词.

B