conclude/ kən'kluːd /

1.vt.
(finish) 结束

2.vt.[+treaty] [ deal] [ agreement] 
缔结

3.vi.[event+] 
to conclude with sth 以某物而告终

4.vi.[speaker+] 
以某物收尾

I'd like to conclude by saying...
我想讲的最后一句话是…
to conclude that...
断定…
"that," he concluded, "is why we did it"
“那,”他断定说,“就是我们这样做的原因”