Travelling is a pleasure. Particularly for the young, the
desire to see new places and get the feel of a new
environment makes travel a wonderful experience. But do
we make it trouble-free for others? Don't start a
conversation with the co-passenger without first knowing
his willingness to converse with you. He/she might like to
read or have a nap and not necessarily be in a mood to
talk. Place your baggage in the rack above your seat. Don't
encroach upon another's space. Also wait till the plane/
bus/ train comes to a stop to pull your luggage out. Be
eco-friendly-remember that the place where you stand
had been visited and has to be visited by thousands more.
Carry a plastic bag for waste on sightseeing trips; you can
empty it later in a dustbin. "Sustainable Tourism" is the
only way to protect the resource and beauty of the earth.
If you want to enjoy the hospitality of friends or relatives
residing in the place you visit, inform them in advance.
Don't drop in like a bolt from the blue. Be considerate
towards your hosts. Help your host/ hostess in domestic
chores. Go on sightseeing trips without troubling them to
come to your help. Use your own toiletries and towels. Use
the telephone of your host sparingly and only when
necessary. Don't interfere in their domestic affairs unless
you are asked to join. Don't expect your host to attend to
your needs all the time.


The idiom 'a bolt from the blue' means


please tell the answer ​