What was the trick originally in ‘trick or treat’?
1. knock on the door and then run away
2. throw water at the person opening the door
3. sing a song to the person giving you the candy
4. recite a good luck protection spell

no , per capita income is not a true measure of the development because: -it only tells us about average income not how income is distributed among the people.it only give us an idea of the economic aspect.it is only at the qualitative basis.moreover, income is not only the way of development other factors are also as much as important as income.

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations.