英语翻译是what are they used to do 和what are they used for doing?

英语翻译是what are they used to do 和what are they used for doing? What are u doing? 连词成句 they what are accident terrible.是they are连词成句 they what are accident terrible.是they are还是are they 英语翻译尤其是for what they are 什么用法 They are u----- the tree. 英语翻译what do they say?they say that they are thirsty what are they What are they? What are they doing? what are they doing? what nice they are What are they What are they? What are they? What islands are they? what are they! what great they are! what are these?怎么回答?是用they are 为什么?