Answer 1

my mother hours to do the housework everyday.

wasn't invented, we couldn't talk to each other so easily whenever we want.

is being built with a three-hundred rooms

appliances should be used instead of...

Answer 2

37. It takes my mother three hours to do the housework every day.

38. If the telephone wasn't invented, we couldn't talk to each other so easily whenever we want.

39. The hospital they are building has three hundred rooms.