Answer the following question given this paragraph: The earliest placental mammals may have evolved about 110 million years ago. The ancestor of placental mammals may be the extinct genus Eomaia . Fossils of Eomaia have been found in what is now China. It was only about 10 centimeters (4 inches) long. It was a tree climber and probably ate insects and worms. Eomaia had several traits of placental mammals. Figure below shows how Eomaia may have looked. Q: What may be the ancestor of placental mammals? Choices: - fungi - spirogyra - amphibians - eomaia A:
eomaia
Answer the following question given this paragraph: Monatomic cations have the same name as their parent element, whereas monatomic anions end in - ide . Q: Monatomic cations have the same name as their parent element. what happens to monatomic anions? Choices: - ends in - se - ends in - fe - ends in - be - ends in - de A:
ends in - de
Q: Answer the following question given this paragraph: Right Atrium The right atrium serves as the receiving chamber for blood returning to the heart from the systemic circulation. The two major systemic veins, the superior and inferior venae cavae, and the large coronary vein called the coronary sinus that drains the heart myocardium empty into the right atrium. The superior vena cava drains blood from regions superior to the diaphragm: the head, neck, upper limbs, and the thoracic region. It empties into the superior and posterior portions of the right atrium. The inferior vena cava drains blood from areas inferior to the diaphragm: the lower limbs and abdominopelvic region of the body. It, too, empties into the posterior portion of the atria, but inferior to the opening of the superior vena cava. Immediately superior and slightly medial to the opening of the inferior vena cava on the posterior surface of the atrium is the opening of the coronary sinus. This thin-walled vessel drains most of the coronary veins that return systemic blood from the heart. The majority of the internal heart structures discussed in this and subsequent sections are illustrated in Figure 19.9. While the bulk of the internal surface of the right atrium is smooth, the depression of the fossa ovalis is medial, and the anterior surface demonstrates prominent ridges of muscle called the pectinate muscles. The right auricle also has pectinate muscles. The left atrium does not have pectinate muscles except in the auricle. The atria receive venous blood on a nearly continuous basis, preventing venous flow from stopping while the ventricles are contracting. While most ventricular filling occurs while the atria are relaxed, they do demonstrate a contractile phase and actively pump blood into the ventricles just prior to ventricular contraction. The opening between the atrium and ventricle is guarded by the tricuspid valve. Q: What guards the opening between the right atrium and the right ventricle? Choices: - superior vena cava - brachiocephalic trunk - aorta - tricuspid valve A:
A: tricuspid valve
Question: Answer the following question given this paragraph: Alkali metals are all solids at room temperature. They are relatively soft and low in density. Q: What property are alkali metals at room temperature? Choices: - mixed - liquid - solid - solid A:
Answer: solid
*Question*
Answer the following question given this paragraph: Xerography Most copy machines use an electrostatic process called xerographya word coined from the Greek words xeros for dry and graphos for writing. The heart of the process is shown in simplified form in Figure 18.39. A selenium-coated aluminum drum is sprayed with positive charge from points on a device called a corotron. Selenium is a substance with an interesting propertyit is a photoconductor. That is, selenium is an insulator when in the dark and a conductor when exposed to light. In the first stage of the xerography process, the conducting aluminum drum is grounded so that a negative charge is induced under the thin layer of uniformly positively charged selenium. In the second stage, the surface of the drum is exposed to the image of whatever is to be copied. Where the image is light, the selenium becomes conducting, and the positive charge is neutralized. In dark areas, the positive charge remains, and so the image has been transferred to the drum. The third stage takes a dry black powder, called toner, and sprays it with a negative charge so that it will be attracted to the positive regions of the drum. Next, a blank piece of paper is given a greater positive charge than on the drum so that it will pull the toner from the drum. Finally, the paper and electrostatically held toner are passed through heated pressure rollers, which melt and permanently adhere the toner within the fibers of the paper. Q: What term is used to describe the electrostatic process used by most copy machines? Choices: - electrography - titanomachy - microphotography - xerography A:
**Answer**
xerography
Q: Answer the following question given this paragraph: The smallest particle of an element that still has the properties of that element is an atom. Atoms are extremely tiny. They can be observed only with an electron microscope. They are commonly represented by models, like the one Figure below . An atom has a central nucleus that is positive in charge. The nucleus is surrounded by negatively charged particles called electrons. Q: What is the smallest particle of an element that still has the properties of that element is called? Choices: - nucleus - neutron - proton - atom A:
A: atom