Answer the following question given this paragraph: The Moon has dark areas, called maria, surrounded by lighter colored highland areas, called terrae. Q: What are the dark areas of the moon called? Choices: - craters - hollow space - laura - maria A:
maria
(Question)
Answer the following question given this paragraph: 47.2 | The Importance of Biodiversity to Human Life By the end of this section, you will be able to: Identify chemical diversity benefits to humans Identify biodiversity components that support human agriculture Describe ecosystem services It may not be clear why biologists are concerned about biodiversity loss. When biodiversity loss is thought of as the extinction of the passenger pigeon, the dodo bird, and even the woolly mammoth, the loss may appear to be an emotional one. But is the loss practically important for the welfare of the human species? From the perspective of evolution and ecology, the loss of a particular individual species is unimportant (however, the loss of a keystone species can lead to ecological disaster). Extinction is a normal part of macroevolution. But the accelerated extinction rate means the loss of tens of thousands of species within our lifetimes, and it is likely to have dramatic effects on human welfare through the collapse of ecosystems and in added costs to maintain food production, clean air and water, and human health. Agriculture began after early hunter-gatherer societies first settled in one place and heavily modified their immediate environment. This cultural transition has made it difficult for humans to recognize their dependence on undomesticated living things on the planet. Biologists recognize the human species is embedded in ecosystems and is dependent on them,. Q: The passenger pigeon, the dodo bird, and the woolly mammoth represent individual cases of what fate? Choices: - isolation - compression - accumulation - extinction A:
(Answer)
extinction
Ques: Answer the following question given this paragraph: Covalent bond energies can be used to estimate the enthalpy changes of chemical reactions. Q: Covalent bond energies can be used to estimate the enthalpy changes of what? Choices: - crystals reactions - Pressure reactions - liquid reactions - chemical reactions A:
Ans: chemical reactions
(Q).
Answer the following question given this paragraph: Ordinary table salt is called sodium chloride. It is considered a substance because it has a uniform and definite composition. All samples of sodium chloride are chemically identical. Water is also a pure substance. Salt easily dissolves in water, but salt water cannot be classified as a substance because its composition can vary. You may dissolve a small amount of salt or a large amount into a given amount of water. A mixture is a physical blend of two or more components, each of which retains its own identity and properties in the mixture . Only the form of the salt is changed when it is dissolved into water. It retains its composition and properties. Q: Ordinary table salt is called what? Choices: - oxygen chloride - carbon chloride - ammonia chloride - sodium chloride A:
(A).
sodium chloride
Ques:Answer the following question given this paragraph: Absorption of light by a hydrogen atom. (a) When a hydrogen atom absorbs a photon of light, an electron is excited to an orbit that has a higher energy and larger value of n. (b) Images of the emission and absorption spectra of hydrogen are shown here. Emission and absorption spectra form the basis of spectroscopy, which uses spectra to provide information about the structure and the composition of a substance or an object. In particular, astronomers use emission and absorption spectra to determine the composition of stars and interstellar matter. As an example, consider the spectrum of sunlight shown in Figure 6.14 "The Visible Spectrum of Sunlight". Because the sun is very hot, the light it emits is in. Q: What are scientists able to determine about stars using emission and absorption spectra? Choices: - shape - size - distance - composition A:

Ans:composition
Ques:Answer the following question given this paragraph: All streams and rivers have several features in common. These features are shown in ( Figure below ). The place where a stream or river starts is its source. The source might be a spring, where water flows out of the ground. Or the source might be water from melting snow on a mountain top. A single stream may have multiple sources. A stream or river probably ends when it flows into a body of water, such as a lake or an ocean. A stream ends at its mouth. As the water flows into the body of water, it slows down and drops the sediment it was carrying. The sediment may build up to form a delta. Q: What is the name of the location in which a stream or river starts? Choices: - spring - shore - mouth - source A:

Ans:
source