单词	双重积分
释义	双重积分double integral
随便看	better not born better not look a gift-horse in the mouth better off better-off better (off) dead better off dead better-of-two option better oneself better one's self (in position, etc.) better part of man's nature better poor with honour than rich with shame. better prenatal care better quality better red than dead/rather be red than dead better ride on an ass that carries me than on a horse that throws me. better round betters better safe than sorry better safe than sorry. better same order bias estimator better self better sell nine things for ready money than ten on credit better small fish than an empty dish. better sort better spare at the brim than at the bottom.