(1)I don’t know what that is.
(2)Do you know where the nearest post office is?
(3)I don’t understand why Ken hates working on Friday afternoons.
(4)Do you know who came to the party?
(5)Do you know when he came?
(6)I don’t know who he is.
(1)I don’t know what that is.
(2)Do you know where the nearest post office is?
(3)I don’t understand why Ken hates working on Friday afternoons.
(4)Do you know who came to the party?
(5)Do you know when he came?
(6)I don’t know who he is.