Lyphilization is another word for freeze drying. Freeze drying can do things like preserve foods. Hikers can be found carrying them because they are lighter. Many products like instant coffee use freeze drying.
American sign language is used by those who are deaf and those who wish to speak with them. This is a manual language and is communicated by symbols not sounds. Some signs can be pretty easy while others are not.
Harriet Tubman was one of the most famous conductors of the under ground railroad! Once free she returned south to help her family escape. Her activities were both successful and well-known.
Hope this is helpful good luck!