They changed drastically because of the Mexican-American war.
Answer:
This is a demand side market failure
Explanation:
Demand side market failure occurs when the business owner selling a particular product is not able to make the buyer pay for that particular product even though it may be in demand around that time.
Example are the Christmas decorations even though they are in demand around Christmas but the fact that they are decorating all over the most places, one can not charge people from looking and enjoying these decorations because they are usual all over the place .
Another example is also fireworks which are fired around Christmas everyone can enjoy them without having paid for them.

The increase of pollutants from maquadelios in Mexico raised concerns about damage to health and the environment.
pollution is the contamination of pollutants such as harmful gases.
Thanks
Answer:
here are some strategies the government can imply to encourage volunteerism.
Explanation:
1) communication is the key- the government should invite influential or keynote speakers to communicate with the general public so that they can talk about the importance of volunteering and encourage them to participate more.
2) provide incentives- if the government starts providing incentives or rewards for volunteering or set targets and goals during the volunteering a healthy competitive spirit is created and people are more than happy to volunteer, its either for the cause or the incentives/benefits.
3) setting role models- actions speak louder than words. if the people see a respected role model could be a celebrity, sportsperson,comedian or their own elected representatives out on the streets doing some volunteering work, the people tend to be inspired from it. thus, follow their footsteps and volunteer.
The Chinese Exclusion Act was a United States federal law signed by President Chester A. Arthur on May 6, 1882, prohibiting all immigration of Chinese laborers.