The Chinese governement caused China to merge with the National Population and Family Planning Commission with the Ministry of Health to create a new National Health and Family Planning Commission. Eight months later, in November 2013, China announced a partial policy relaxation that allowed couples to have two children if one parent is an only child.
Answer: Through multiple revolutions, people have adapted to and affected their environments. As civilizations settled, new advances in agriculture and tools were made to allow for a less-nomadic society. Through advances such as iron tools and food stock, civilizations settled creating the basis for large empires to come later. Also through the innovation of weapons and armor, empires were able to better control and defend larger territory allowing for exponential expansion. Finally, with new advances made by different civilizations, trade increased as demand for new products from other empires grew.
Some factors that may make it difficult to keep speed during a stairway evacuation are exhaustion or the person's mental state. During a period of evacuation, the stress suffered is going to affect how people are going to respond, and how they are going to react. Also, the architecture of the stairway may affect the stairway evacuation process.