21, While my father ( do ) morning exercise, he heard her voice.
→......................................................................................................
22, It is dangerous ( put ) a knife in a socket.
→......................................................................................................
23, I don’t mind ( look ) after my brother.
→......................................................................................................
24, He ( have ) a leg broken when he ( play ) football.
→......................................................................................................
25, Miss Hoa is ashamed, so she avoids ( meet ) other people.
→......................................................................................................
26, Yesterday, we ( spend ) a lot of money ( buy ) this book.
→......................................................................................................
27, It is no use ( repair ) that bike.
→......................................................................................................
28, Lam as well as his parents ( visit ) Ha Long at the moment.
→......................................................................................................
29, Her mother used ( get ) up early when she ( live ) in the countryside.
→......................................................................................................
30, The students ( take ) an exam by this time tomorrow.
→......................................................................................................