Did you find the key _____the door?[ ]

My mother and I will go to Shanghai this summer. 　　—______. Shall we go together?

He told us that he was tired and thirsty because he ________ in the desert for days.

Could I have ________ apples? Sorry, we don’t have ________ apples.

How is it that you know she’s got back from the UK? —She ____ when I came out of the house this morning.