He says he has drink his milk.这句是什么时态?

题目

He says he has drink his milk.这句是什么时态?
新概念一,第102课,课后练习：
书中给出的例句：He is drinking his milk.
改成间接引语后：He says he has drink his milk.
这个间接引语我会改,我不懂的是这句中的has drink his milk中的has是什么作用,这句中我也知道has是have的第三人称单数形式,那如果换成其他人称如第三人称复数,they say they have drink their milk.这里have drink是什么意思,drink本身都是喝了,为什么还有个have.原句中到底has是干什么的.
以下是给出的题：
1、she is shutting the door.
改后：she says she has shut the door.
2、he is putting on his coat.
改后：he says he has put on his coat.
3、he is reading this magazine.
改后：he says he has read this magazine.
4、they are speaking to the boss.
改后：they say they have spoken to the boss.
5、the sun is rising.
改后：they say the sun has risen.
改过后的句子中都有have/has,很糊涂.

答案

应该是主句是一般现在时态,从句的间接引语是现在完成时态,表示已经做过什么什么事情了,还有你给的列子应该是打错了,应该是He says he has drunk his milk.翻译成他说他已经喝过牛奶了.在100多课有这个时态的详细讲解.