现在完成时中的 twice once等等 是用how long 还是how ofen we have been to china twice用什么提问划线部分 twice

现在完成时中的 twice once等等 是用how long 还是how ofen we have been to china twice用什么提问划线部分 twice Wit once bought is worth twice taught .中的bought是什么意思? Once bitten,twice shy. once bitten twice once/twice/three times a once twice thrice接下去是什么? Once Bitten Twice Shy 歌词 Some students exercise once or twice a once twice 后面的英语单词接下去是什么? once a week和twice a week once or twice a week 中文意思 once or twice a week 造句 work once and work twice 翻译 once bitten,twice shy的意思 once half year,twice a year Once a man and twice a child. I shop once or twice a month 划线部分 once or twice a month 提问 The stadents exercise once or twice a week对once or twice提问