What complicates the issue is the burden of history. [VERB noun]

历史的重负使问题复杂化了。

The day's events, he said, would only complicate the task of the peacekeeping forces. [VERB noun]

他说白天发生的事件只会使维和部队的任务更为复杂。

To complicate matters further, everybody's vitamin requirements vary. [VERB noun]

更麻烦的是，每个人对维生素的需求量是不同的。

Bad weather continues to complicate efforts to deal with oil spilling from the tanker. [VERB noun]

恶劣天气使得油轮溢油的处理工作更为复杂。