Reference librarians are specially trained to patrons perform what task?
a. sign out dvds
b. research a topic
c. apply for a library card

Reference librarians are specifically trained to help patrons B) Research a topic. They investigate a common information to help the people in the Library. 

To form soil, the two processes which must occur are erosion and weathering, so the correct answer is "soil formation is a continuous presses, but also one which takes a long time, it can sometimes take more than five hundred years for 1cm of soil to form.