The immune system includes certain types of white blood cells. It also includes chemicals and proteins in the blood, such as antibodies, complement proteins, and interferon. Some of these directly attack foreign substances in the body, and others work together to help the immune system cells.
Scott Joplin. Scott Joplin was the best-known American ragtime musician and composer, setting the standard for all that followed. Ragtime â which gave birth to Jazz â has a rhythm in which the accompaniment is strict two-four time and the melody, with improvised embellishment, is in steady syncopation. Joplin`s instrument of choice was the piano. Early days
This short poem is one of Hughesâs most famous works; it is likely the most common Langston Hughes poem taught in American schools. Hughes wrote Harlem in 1951, and it addresses one of his most common themes - the limitations of the American Dream for African Americans.