Questions

I am a Barber.

The size of the pupil of the automatically adjusts itself according to the intensity of light passing through it; if the intensity is more, the size is less, if less, it is more. So in our case the pupil should dilate i.e , increase in size to be able to see in the dark. This switchover takes some time. But here the entry into the dark room is immediate. So the eye has no time to adjust itself and hence is not able to see at all for a while. 

The process which wherein an Ecosystem may renew itself is known as Ecological Succession.

The time scale may be decades or a million of years after a mass extinction. 

It may be achieve over a period of time.

A Project Management office (PMO) is an organizational unit to centralize and coordinate the management of projects under its domain. A PMO can also be reffered to as a "program management office", "Project office", or "Program office". A PMO oversees the management of projects, programs, or a combination of both.

PMOs can operate on a continuum, from providing project management support functions in the form of training, software, standardized policies, and procedures, to actual direct management and responsibility for achieving the project objectives.

It gets contaminated by lead

Friend is a person with whom one has a bond of mutual affection, typically one exclusive of sexual or family relations.

Other names for friend are mate, bosom friend, classmate, buddy, ally,...

A colored ion generally indicates a transition metal.