The man who is giving a lecture.【who】能不能改成【that】?为什么不是完整的句子？

Who is the man. Who is the man who is the best man 请问who is the man Who is the old man? Happy is the man who is received Who is the first man in space? who is the man?怎么回答? Who is the man in a u Who is the talleat man?中文意思. Who is the shortest man 中文意思. Wise is the man who stops a 请问Do you konw who is the man还是Do you know who the man is Who is the man?里 主语是the man 谓语是is 宾语是who吗? who is the man 前面要加什么时才要变成who the man is? The man who is under the tree is my father. The right man is the one who sizes the mmoment. The man who is standing there.可不可以改成The man who stand there.