The layered implementation, however, presents problems such as code complexity, dataaccumulation, and difficulty of debugging.
但是，层状的执行会出现诸如代码复杂性、数据积累以及调试困难之类的各种问题。
2
But despite the passage of time and the accumulation of supporting data, teaching evolutionary theory in the classroom is still a hot-button issue in some U.S. schools.
纵使时间推移，数据累积，在美国的一些学校，进化论能否进入课堂仍是一个热点问题。
3
An initiatives portfolio contains a number of individual initiatives, their identification data, and an accumulation of performance data.