ES有关按时间排序后，返回的结果中没有搜索的关键词的问题。

问题描述：
我在查询关键词“新闻”时，返回了所有包含 “新闻” 关键词的数据。
此时我想让数据按时间先后顺序排序。
于是我添加 了sort 语法，但是搜索到的结果 以时间的先后顺序排列了，但是返回的结果中没有包含“新闻”关键字，（即query 查询语句使用sort 后，查询条件失效了。）


没有添加sort 排序的语法：
{
"from": 0,
"highlight": {
"fields": {
"content": {},
"description": {},
"title": {}
}
},
"query": {
"multi_match": {
"fields": [
"title",
"keywords",
"extensionkeywords",
"description",
"content"
],
"operator": "and",
"query": "新闻"
}
},
"size": 10
}

返回的部分数据如下：

(
[took] => 14
[timed_out] =>
[_shards] => Array
(
[total] => 5
[successful] => 5
[failed] => 0
)

[hits] => Array
(
[total] => 551
[max_score] => 45.696007
[hits] => Array
(
[0] => Array
(
[_index] => index
[_type] => honda
[_id] => 9826ccf56a4f76ff7c967598120bb48a
[_score] => 45.696007
[_source] => Array


以下是我添加sort的查询语法：

{
"from": 0,
"highlight": {
"fields": {
"content": {},
"description": {},
"title": {}
}
},
"query": {
"multi_match": {
"fields": [
"title",
"keywords",
"extensionkeywords",
"description",
"content"
],
"operator": "and",
"query": "新闻"
}
},
"size": 10,
"sort": [
{
"date": {
"order": "desc"
}
}
]
}

返回的数据

(
[took] => 15
[timed_out] =>
[_shards] => Array
(
[total] => 5
[successful] => 5
[failed] => 0
)

[hits] => Array
(
[total] => 551
[max_score] =>
[hits] => Array
(
[0] => Array
(
[_index] => index
[_type] => honda
[_id] => 9826ccf56a4f76ff7c967598120bb48a
[_score] =>
[_source] => Array


两次查询返回的 total 都是 551 ， 但是 max_score 与 _score 不同

求大神帮我看一看为什么，怎么解决？