建筑工程已经在进行中了。

The construction project is already ___be ___under ___way.

为找到解决方案，研究工作正在进行中。

Research studies ___are ___under ___way to find a solution.

和平谈判正在联合国总部进行中。

The peace negotiations ___are ___under ___way at the United Nations headquarters.