CPC's ruling legitimization faces many challenges during the transformation period. 转型时期执政党的执政合法性面临诸多挑战。
The time scale of variations with the second period is still uncertain due to the limitation of data time length. 由于数据时间长度的限制,气候转型的时间尺度还不明确,也不清楚其是否有明显的周期性。