11.   There are other issues simmering beneath the surface that could cost him votes.

12.   What is simmering beneath the criticism is a deep rift over the role of Pope Pius XII during the war.

13.   You know, simmering beneath the surface.

14.   Many are wondering if the social tension always simmering beneath the surface here could bubble up soon.

15.   Other problems simmer just beneath the surface.