Interpreting the question as kglr has donedone, and using listA and listB as given in kglr's answeranswer:
Cases[listA, {#, x_} :> Sequence[#, x]] & /@ listB /. {} -> Null
{Null, {10, 0.239651}, {1, 0.00869692}, {9, 0.181763},
{9, 0.181763}, Null, Null, {6, 0.074256}, {3, 0.0413228}, Null}
Or
Cases[listA, {#, x_} :> Sequence[#, x]] & /@ listB /. {} -> Nothing
{{10, 0.239651}, {1, 0.00869692}, {9, 0.181763}, {9, 0.181763},
{6, 0.074256}, {3, 0.0413228}}