Putting a knife into an electrical socket is dangerous.

• It is dangerous to put a knife into an electrical socket.

Driving too fast is dangerous.

• It's dangerous to drive too fast.

Leaving the medicine around the house is not safe.

• It's not safe to leave the medicine around the house.

It is good exercise to run a mile a day.

• Running a mile a day is good exercise.

It is interesting to go swimming in the river in the summer.

• Going swimming in the river in the summer is interesting.

It is great pleasure to be with you.

• Being with you is great pleasure.

Living with my family is always happiness to me.

• It's always happiness to me to live with my family.

It's not good to talk in class while the teacher is explaining the lesson.

• Talking in class while the teacher is explaining the lesson is not good.

Complaining all day is one of her habits.

• It's one of her habits to complain all day.

Playing football is good for your health.

• It's good for your health to play football.

It is interesting to participate in school activities.

• Participating in school activities is interesting.

Recycling paper and cans is necessary.

• It's necessary to recycle paper and cans.

It isn't safe to climb high mountains alone in the winter.

• Climbing high mountains alone in the winter isn't safe.

Helping poor children is a good activity.

• It's a good activity to help poor children.

Keeping the environment clean is very important.

• It's very important to keep the environment clean.