When infection attacks the body, anti-infective drugs can suppress the infection. Several broad types of anti-infective drugs exist, depending on the type of organism targeted; they include antibacterial (antibiotic; including antitubercular), antiviral, antifungal and antiparasitic (including antiprotozoal and antihelminthic) agents. Depending on the severity and the type of infection, the antibiotic may be given by mouth or by injection, or may be applied topically. Severe infections of the brain are usually treated with intravenous antibiotics. Sometimes, multiple antibiotics are used in case there is resistance to one antibiotic. Antibiotics only work for bacteria and do not affect viruses. Antibiotics work by slowing down the multiplication of bacteria or killing the bacteria. The most common classes of antibiotics used in medicine include penicillin, cephalosporins, aminoglycosides, macrolides, quinolones and tetracyclines.[citation needed]
How many broad types of anti-infective drugs exist?
Several

Rufinus relates a story that as Bishop Alexander stood by a window, he watched boys playing on the seashore below, imitating the ritual of Christian baptism. He sent for the children and discovered that one of the boys (Athanasius) had acted as bishop. After questioning Athanasius, Bishop Alexander informed him that the baptisms were genuine, as both the form and matter of the sacrament had been performed through the recitation of the correct words and the administration of water, and that he must not continue to do this as those baptized had not been properly catechized. He invited Athanasius and his playfellows to prepare for clerical careers.
As a child, Athanasius imitated what ritual?
ritual of Christian baptism

Ye Zhiping, the principal of Sangzao Middle School in Sangzao, one of the largest in An County, has been credited with proactive action that spared the lives of all 2,323 pupils in attendance when the earthquake happened. During a three-year period that ended in 2007, he oversaw a major overhaul of his school. During that time he obtained more than 400,000 yuan (US$60,000) from the county education department, money used to widen and strengthen concrete pillars and the balcony railing of all four storeys of his school, as well as secure its concrete floors.
The Sangzao school is one of the biggest in what county?
An County