A.responseText B.responsetext C.responseXML D.responsexml
A.setRequestHeader("Connection","close"); B.xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded"); C.setRequestHeader("Content-length",paramsSend.length); D.以上都不正確
A.請求已發(fā)送(這里通??梢詮捻憫?yīng)得到內(nèi)容頭部) B.請求已提出(調(diào)用send()之前) C.請求未初始化 D.服務(wù)器連接已建立