Lasers
Laser lights are used in CD and DVD players. They are used in grocery stores to scan bar c...
Endangered species are animals that are in danger of becoming extinct. Extinction means that there are no longer any living animals of a particular kind. For this reason, when there are only a few of a particular type of animal in a specific area, a government agency often identifies it as being endangered, or in danger of dying out. Animals can become endangered because people hunt them for their value. Other types of human behavior can also cause harm to animals such as boat usage in lakes, rivers, and oceans. The propellers of boats can harm certain types of animals in the water. Damage to certain places where animals live can also make it difficult for animals to survive. Disease and pollution can also eliminate animals. The more animals that are endangered, the fewer animals there will be. Supporting programs to protect threatened animals and the environment is very important.
Laser lights are used in CD and DVD players. They are used in grocery stores to scan bar c...
Even though many of the inventions introduced in the past one hundred years have contribut...
Many of us wear watches, which are more accurately called wristwatches. Why did a portable...