应急电源的控制板烧坏的主要原因是充电电流过大，或电池电压（）。
参考答案：太低
The performance ______ nearly three hours, but few people left the theatre early. [ ]
A. covered
B. reached
C. played
D. lasted
目标成果评估的主要步骤有（）
A.自我评估
B.工作者评估
C.小组评估
