Rewrite the sentences in the same meaning

11.    China has the largest population in the world.
    There are not ……………………………………..
12.    The book really interests me.
    I am ………………………………………
13.    They didn’t go fishing because it was too cold.
    If it …………………………………………….
14.    When did you start learning English ?
    How long _______________________________________________________________
15.    I’m sorry I was so rude to you yesterday.
    I apologize ______________________________________________________________
16.    People say she is an honest and reliable person.
    It is ___________________________________________________________________
17.    It took me two hours to do my homework. 
    I ______________________________________________________________________
18.    He left school and then joined the army.
    After he ________________________________________________________________
19.    What is your date of birth ?
    When __________________________________________________________________
20.    When Minh was small, he usually slept with his brother.
    Minh used ______________________________________________________________