He often works by rule of thumb.他通常凭经验办事.As a rule of thumb, a cup of filter coffee contains about 80mg of caffeine.凭经验估计，一杯过滤咖啡约含80毫克咖啡因。A good rule of thumb is that a broker must generate sales of ten times his salary ...

n.凭感觉的方法，单凭经验的方法，经验法则，拇指规则...

rule of thumb的音标：rule of thumb的英式发音音标为：[ru:l ɔv θʌm]rule of thumb的美式发音音标为：[rul ʌv θʌm]...