疑问句中,陈述句形式该怎么写?如：I want to know when we should arrive at the airprot?

疑问句中,陈述句形式该怎么写?如：I want to know when we should arrive at the airprot?
我要像主语 谓语之类该写在什么什么的后面 就是格式
选择题一般这样写I want to know _______ A.when should we arrive at the airport B.when we should arrive at the airport......该怎么分辨能正确答题