在波形梁板镀锌层均匀性测试中，试样经硫酸铜溶液侵蚀15次后不变红，则认为合格。
参考答案：错
All the task _____ ahead of time, they decided to go on holiday for a week. [ ]
A. had been finished
B. were finished
C. having been finished
D. been finished
美在无意识说
