41.   We were waiting for the bus for half an hour.

42.   You were supposed to be here half an hour ago.

43.   Start with ten minutes of exercises each day and work up to half an hour.

44.   The weather can change completely in as little as half an hour.

45.   We spent half an hour looking for the keys, but eventually gave up and went home.

46.   We stood in a queue for half an hour.

47.   Instead of using the money to pay his rent, he went to a betting shop and lost the lot in half an hour.

48.   After half an hour, the fish stopped biting and we moved on.