Answer the following question given this paragraph: Even though large life forms have been very successful on Earth, most of the life forms on Earth today are still prokaryotessmall, relatively simple single-celled organisms. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; in fact, it is estimated that 99% of the species that have ever lived on Earth no longer exist. Q: An estimated 99 percent of the species that have ever lived on earth no longer exist, showing that what event is common? Choices: - accumulation - over fishing - pollution - extinction A:
extinction

Answer the following question given this paragraph: Introduction to Linear Momentum and Collisions We use the term momentum in various ways in everyday language, and most of these ways are consistent with its precise scientific definition. We speak of sports teams or politicians gaining and maintaining the momentum to win. We also recognize that momentum has something to do with collisions. For example, looking at the rugby players in the photograph colliding and falling to the ground, we expect their momenta to have great effects in the resulting collisions. Generally, momentum implies a tendency to continue on courseto move in the same directionand is associated with great mass and speed. Momentum, like energy, is important because it is conserved. Only a few physical quantities are conserved in nature, and studying them yields fundamental insight into how nature works, as we shall see in our study of momentum. Q: Generally, momentum implies a tendency to continue on courseto move in the same directionand is associated with great mass and speed. momentum, like energy, is important because it is what? Choices: - endless - sequences - invisible - conserved A:
conserved

Answer the following question given this paragraph: The molecular mass is the sum of the masses of the atoms in the formula. Q: The sum of the masses of the atoms in the formula is referred to as what? Choices: - nucleus mass - magnetic mass - atomic mass - molecular mass A:
molecular mass