what is in the middle of the USA?(脑筋急转弯）

what is in the What is in the chinatown? What is in the middle in China what is the biggest in the world What is the problem in the story? what is the problem in the what is the city like in the passage?what is the city like in the passage? what is the weather like in December? What table is in the field what is the longest word in English What is love in the end? what table is in the field what table is in the field What is in the middle of Pairs what is the average salary in china What is the weather like in w What is there in the kitchen?是什么意思 in the afternoon.what is it?