某厂去年计划产值80万元，实际增产20万元．实际比计划增产百分之几？
答：20÷80=25%；
答：实际比计划增产25%．
I cleaned my classroom ______. [ ]
A. with three hours
B. three hours ago
C. in three hours
D. three hours before
饭店服务质量有哪些特点？
