单因素试验
参考答案：
在同一试验中只研究某一个因素的若干处理的试验。
Since the end of World War Ⅱ, teachers have found themselves under considerable pressure to abandon the long-standing ______ model, though it had been in general use in second language teaching since the late 18th century.
供应商私自与基层矿厂联系送货，经核实属实的，（），所送物资不予结算。
A、取消供应资格
B、追究矿厂责任
C、提出书面警告
D、给予罚款处理
