What are they( ) on the Christmas tree 括号里填什么?

是What on earth are they looking at?还是What on earth they are looking at? They live on,even when we're gone.What Are What are they doing now? They_(put)on their clothes. 猜猜是什么英语单词?they are green .they are not hravy.they are on three,children.sometimes collect them beause they are pretty .what are they? when we put on them,they are full.but they are empty when we dont use them.what are they? 请问what are on the desk?they are some apples on the desk.有语法错误吗? 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! are they on the