铁路道砟产品必须水洗，其颗粒表面清洁度不应大于（），未经水洗的一级道砟中粒径0.1mm以下的粉末的含量不应大于（）。
参考答案：0.17%；1%
动物福利的原则是（）。
Mary A Contrary has a SHORT position in 15 November heating oil contracts. She buys 15 December heating oil contracts. Ms. Contrary has:()
A. closed her futures position by offset.
B. initiated a new LONG futures position in addition to her existing SHORT position.
C. initiated an exchange-for-physicals (EFP).
