Mrs. Brown was much disappointed to see the washing machine she had had _______ went wrong again.

The noise from the top floor，loud and constant，of the meeting-room_________ can be clearly heard in our classroom．

 ____ by high mountains, the city is infamous for air pollution. 

I got to the office earlier that day,   the 7:30 train from Paddington.

 I don’t think it easy, even if we work hard, ______ the South Korea and the North Korea to sit down to talk at present.