Go to your  Writing Mentor. Read the definitions and practice correcting the following common writing mistakes:

Run-on sentence

Comma Trauma

Period Stops

It's in the Past

Now test your skills and correct the following paragraphs. (Game)

After the Passage into North America. 

(1) the Adenans were the first Indians to build mounds, in what is now the United States most of these earth mounds were burial sites and fortifications around 600 B.C. Some mounds from that era will be in the shape of birds or serpents, and they probably served religious purposes not yet fully understood. 

(2) The adenans appear to have been absorbed or displaced by various groups known as Hopewellians one of the most important centers of their culture was found in southern Ohio where the remains of several thousand of these mounds still remain.  the Hopewellians used and exchanged tools and materials. Across a wide region of hundreds of kilometers. There were supposedly great traders.

By around 500 A.D., the Hopewellians, too, have disappeared, gradually giving way to a group of tribes making up the Mississippians or Temple Mound culture. One city, Cahokia, just east of St. Louis, Missouri, is thought to have reached a population of about 20,000 in the early 12th century. A huge earthen mound, flatted at the top, stood at the center of the city it was 30 meters high and 37 hectares at the base. Eighty other mounds have been found nearby.

(Information taken from the U.S. Department of State's Bureau of International Information Programs: http://usinfo.state.gov/products/pubs/history/ch1.htm)