preoperational stage前运思期;前运算阶段;前运思阶段又称“前运算阶段
preoperational test空转试验;运行前的试验
preoperational testing运转前测试
preoperational period前运算阶段;运思前期
preoperational stag前运算阶段
preoperational amplifier运转前放大器
preoperational thinking前运思
preoperational evaluation术前评价