Q: Answer the following question given this paragraph: Puberty in girls starts when the hypothalamus "tells" the pituitary gland to secrete hormones that target the ovaries. Two pituitary hormones are involved: luteinizing hormone (LH) and follicle-stimulating hormone (FSH) . These hormones stimulate the ovary to produce estrogen . Estrogen, in turn, promotes growth and other physical changes of puberty. It stimulates growth and development of the internal reproductive organs, breasts, and pubic hair (see Figure below ). You can watch an animation of these and other changes that girls experience during puberty at this link: http://www. bbc. co. uk/science/humanbody/body/interactives/lifecycle/teenagers/ . Q: What item starts puberty in girls? A: | OPTIONS:
- the ovary
- the uterus
- the thyroid
- the hypothalamus
A: the hypothalamus

Q: Answer the following question given this paragraph: Ionic Compounds The substances described in the preceding discussion are composed of molecules that are electrically neutral; that is, the number of positively charged protons in the nucleus is equal to the number of negatively charged electrons. In contrast, ions are atoms or assemblies of atoms that have a net electrical charge. Ions that contain fewer electrons than protons have a net positive charge and are called cations. Conversely, ions that contain more electrons than protons have a net negative charge and are called anions. Ionic compounds contain both cations and anions in a ratio that results in no net electrical charge. Q: Ions that contain fewer electrons than protons have a net positive charge and are called what? A: | OPTIONS:
- oxides
- particles
- anions
- cations
A: cations

Q: Answer the following question given this paragraph: There are many examples in the chemical world of changes in entropy. Phase transitions are one obvious example. When a substance makes a transition from the liquid state to the gaseous state, the particles have many more possible arrangements, because they are no longer confined to a specified volume in which they are close to each other; gas particles can move freely throughout their container. Vaporization represents an increase in entropy. In the opposite direction, a liquid loses entropy when it freezes to a solid. Because solids have very ordered structures, there are fewer possible arrangements of particles that would result in the properties associated with a solid. Q: The phase transition of a substance changing from a liquid state to a gaseous state is an example of what? A: | OPTIONS:
- trichina
- spirogyra
- catostrophy
- entropoy
A: entropoy

Q: Answer the following question given this paragraph: The pressure of the earth's atmosphere, as with any fluid, increases with the height of the column of air. In the case of earth's atmosphere, there are some complications. The density of the air is not uniform but decreases with altitude. Additionally there is no distinct top surface from which height can be measured. We can, however, calculate the approximate difference in pressure between two altitudes using the equation . The average pressure of the atmosphere at sea level is 1.013 10 5 Pa. This pressure is often expressed as 101.3 kPa. Q: What happens to the density of air as the altitude decreases? A: | OPTIONS:
- multiplies
- remains the same
- increases
- decreases
A: decreases