[译] 他们讨论如何促进两国的合作。
[误] They discussed to promote cooperation between the two countries.

[正] They discussed how to promote cooperation between the two countries.
[注] discuss 后一般不直接跟不定式作宾语，但可以接连接收（副）词引起的不定式短语，也可以接动名词短语作宾语。如：They will discuss giving further help to the flooded area. 他们将讨论给予灾区更多的援助。