There are many different kinds of sewage treatment plants which vary in the process by which they treat wastewater. Generally, they can be classified into the following types of system: 1  Activated sludge plant (ASP). 2  Rotating disc system. 3  Submerged aerated filter (SAF). 4  Suspended Media Filters (SMF).
In certain species of sea life, male pregnancy is common. The male incubates and births live young instead of the female. Human males are not able to do so, and medical risks of a male pregnancy are extreme. Transgender individuals can become pregnant if reproductive organs are left intact. A common phenomenon is a sympathetic pregnancy, where a man exhibits all the symptoms of pregnancy along with his expectant partner.
Teenage pregnancy. Teenage pregnancy is pregnancy in females under the age of 20. A female can become pregnant from sexual intercourse after she has begun to ovulate which can be before her first menstrual period (menarche), but usually occurs after the onset of her periods. In well-nourished females, menarche usually takes place around the age of 12 or 13.