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.
When a woman is pregnant, her date of confinement is generally her due date, or the date when she is expected to give birth. The doctor determines the woman's estimated date of confinement based on the first day of her last menstruation. A full-term pregnancy usually is 37 to 42 weeks, with the due date somewhere in the middle.