under-fives英'ʌndərf'aɪvz美'ʌndərf'aɪvzCOCA²⁸⁰¹³⁶⁺⁵BNC²⁸⁴²⁶Economist⁵³⁵⁸¹⁺¹ 基本例句 n.小于5岁的儿童 The study, conducted by Plymouth Council, surveyed the internet habits of423 under-fives, with an average age of four. 此项研究由普利茅斯委员会发起,调查了423名五岁以下儿童的上网习惯,他们平均年龄为四岁。 changsha