R. N. 1. registered nurse 注册护士 2. Royal Navy
P. r. n. 【医】 需要时, 必要时
r s ratio abbr. =response-stimulus ratio 刺激-反应率
R S nomenclature 【化】 R-S命名法
three R’s read write arithmetic 听写算
three r's n. (儿童教育的基础)读,写,算
the three R's 读.写.算
three R's n. (儿童教育的基础)读,写,算 reading, writing and arithmetic(These three words do not all start with the lett
the three r's 读.写.算
S R mechanism 【化】 S-R机理; 自由基取代反应机理