IV. Complete the sentences using words in bracket.
6) While we __________________ (run) in the park, Mary fell over.
7) His mother is unhappy _________________ (because/ because of) his room is untidy.
8) Alice ___________________ (see) the accident when she was catching the bus.
9) He said that He _______________________ (not/visit) the US before.
10) If we travel to Hanoi, we_____________________ (visit) the museums.
Running , because of , saw, didn't visit , wil visit