However, a subgroup who rated echinacea's effectiveness highly on a form at the start of the study — and were given a placebo during the study — had the shortest duration colds.
然而，在研究开始时分发的表格中高度认同紫锥菊疗效、并在研究中得到安慰剂的那组病人感冒病程最短。
2
The autotransformer is capable of withstanding surge by25times of rated current for2-second duration without any thermal or mechanical damage.
变压器能够承受25倍额定电流持续2秒钟冲击不会造成自耦变压器的任何热和机械损伤。
3
The meows that were rated most pleasant were shorter in duration, had higher frequencies and tended to change from high to low notes.