How are you feeling here? — It’s quite hot. I don’t know _____ to go or stay.

“Well done, John! Not a single mistake ________ in your exam paper this time!” said the teacher．

Some of you may have finished unit one._____; you can go on to unit two.

Whose is this T-shirt?— It’s , the girl under the tree.

______ is impossible if you put your heart into it.