*Question*
Answer the following question given this paragraph: Encephalitis is a brain infection most often caused by viruses. The immune system tries to fight off a brain infection, just as it tries to fight off other infections. But sometimes this can do more harm than good. The immune system's response may cause swelling in the brain. With no room to expand, the brain pushes against the skull. This may injure the brain and even cause death. Medicines can help fight some viral infections of the brain, but not all infections. Q: What is most often the cause of encephalitis? Choices: - parasites - bacterial infections - calcium buildup - viruses A:
**Answer**
viruses

*Question*
Answer the following question given this paragraph: Attached to the placenta is the amniotic sac , an enclosed membrane that surrounds and protects the fetus. It contains amniotic fluid , which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. Q: What is the enclosed, fluid-filled membrane that surrounds and protects the fetus and is attached to the placenta? Choices: - epithelial sac - umbilical sac - womb - amniotic sac A:
**Answer**
amniotic sac

*Question*
Answer the following question given this paragraph: 6.3 The Laws of Thermodynamics In studying energy, scientists use the term "system" to refer to the matter and its environment involved in energy transfers. Everything outside of the system is called the surroundings. Single cells are biological systems. Systems can be thought of as having a certain amount of order. It takes energy to make a system more ordered. The more ordered a system is, the lower its entropy. Entropy is a measure of the disorder of a system. As a system becomes more disordered, the lower its energy and the higher its entropy become. A series of laws, called the laws of thermodynamics, describe the properties and processes of energy transfer. The first law states that the total amount of energy in the universe is constant. This means that energy can't be created or destroyed, only transferred or transformed. The second law of thermodynamics states that every energy transfer involves some loss of energy in an unusable form, such as heat energy, resulting in a more disordered system. In other words, no energy transfer is completely efficient and tends toward disorder. Q: In studying energy, what term do scientists use to refer to the matter and its environment involved in energy transfers? Choices: - molecule - ecosystem - world - system A:
**Answer**
system

*Question*
Answer the following question given this paragraph: Water cycling is extremely important to ecosystem dynamics. Water has a major influence on climate and, thus, on the environments of ecosystems, some located on distant parts of the Earth. Most of the water on Earth is stored for long periods in the oceans, underground, and as ice. Figure 46.13 illustrates the average time that an individual water molecule may spend in the Earth's major water reservoirs. Residence time is a measure of the average time an individual water molecule stays in a particular reservoir. A large amount of the Earth's water is locked in place in these reservoirs as ice, beneath the ground, and in the ocean, and, thus, is unavailable for short-term cycling (only surface water can evaporate). Q: What important liquid is stored throughout the earth in the oceans, underground, and in ice? Choices: - oil - lava - air - water A:
**Answer**
water