工程师们正在修建水坝以防止洪水。

Engineers are ___damming the stream to prevent flooding.

工人们正在筑坝拦截河流，以便建造新的水库。

The workers are ___damming the river to build a new reservoir.

他努力压抑着自己的泪水，不想在公共场合哭出来。

He was ___damning back his tears, not wanting to cry in public.