Answer:
Formaldehyde is a highly reactive molecule that can be directly irritating to tissues with which it comes into contact. Human and animal studies indicate that formaldehyde, at certain exposure levels, can be irritating to the upper respiratory tract and eyes with inhalation exposure, to the skin with dermal exposure, and to the gastrointestinal tract with oral exposure. Formaldehyde-induced noncancer and cancer effects appear to occur only at portals-of-entry (i.e., upper respiratory tract, gastrointestinal tract, and skin).
Answer:
Index
Explanation:
a list (as of bibliographical information or citations to a body of literature) arranged usually in alphabetical order of some specified datum (such as author, subject, or keyword):
Answer: Four geological ages.
Explanation:
he development of the country is divided into four geological ages, prehistoric or Precambrian, ancient or Palaeozoic, Middle Ages Mesozoic, and New Age Cenozoic.
- The Precambrian period begins after the formation of the Earth's crust and lasts about 4 billion years, and it is the oldest and most extended period of Earth's history.
- The beginning of the old age was marked by intense volcanic activity and the Ice Age.
- The Middle Ages were the period of the dinosaurs who were the dominant beings of that period.
- The new age, or the age of mammals, begins with the change of the warm and cold periods and continues to this day.
