Ques:Answer the following question given this paragraph: Benzoic acid crystals in polarized light are pictured above. Benzoic acid is widely used as a food preservative, either as the carboxylic acid or as the sodium benzoate salt. This compound is most effective when added to acidic foods such as fruit juices and soft drinks. The major industrial source of benzoic acid is the partial oxidation of toluene with oxygen. The process is inexpensive and environmentally benign. Q: What type of acid is often used as a preservative for acidic foods such as fruit juices? Choices: - hydrochloric acid - sulfuric acid - citric acid - benzoic acid A:

Ans:benzoic acid
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Ques:Answer the following question given this paragraph: 26.1 Physics of the Eye The eye is perhaps the most interesting of all optical instruments. The eye is remarkable in how it forms images and in the richness of detail and color it can detect. However, our eyes commonly need some correction, to reach what is called "normal" vision, but should be called ideal rather than normal. Image formation by our eyes and common vision correction are easy to analyze with the optics discussed in Geometric Optics. Figure 26.2 shows the basic anatomy of the eye. The cornea and lens form a system that, to a good approximation, acts as a single thin lens. For clear vision, a real image must be projected onto the light-sensitive retina, which lies at a fixed distance from the lens. The lens of the eye adjusts its power to produce an image on the retina for objects at different distances. The center of the image falls on the fovea, which has the greatest density of light receptors and the greatest acuity (sharpness) in the visual field. The variable opening (or pupil) of the eye along with chemical adaptation allows the eye to detect light intensities from the 10 lowest observable to 10 times greater (without damage). This is an incredible range of detection. Our eyes perform a vast number of functions, such as sense direction, movement, sophisticated colors, and distance. Processing of visual nerve impulses begins with interconnections in the retina and continues in the brain. The optic nerve conveys signals received by the eye to the brain. Q: What conveys signals received by the eye to the brain? Choices: - motor nerve - sciatic nerve - sensory nerve - optic nerve A:

Ans:optic nerve
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Ques:Answer the following question given this paragraph: A small child darts in front of your bike as you race down the street. You see the child and immediately react. You put on the brakes, steer away from the child, and yell out a warning, all in just a split second. How do you respond so quickly? Such rapid responses are controlled by your nervous system. The nervous system is a complex network of nervous tissue that carries electrical messages throughout the body. It includes the brain and spinal cord, the central nervous system , and nerves that run throughout the body, the peripheral nervous system (see Figure below ). To understand how nervous messages can travel so quickly, you need to know more about nerve cells. Q: What is the complex network of nervous tissue that carries electrical messages throughout the body? Choices: - respiratory system - circulatory system - lymphatic system - nervous system A:

Ans:nervous system
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Ques:Answer the following question given this paragraph: To keep their flight muscles well supplied with oxygen, birds evolved specialized respiratory and circulatory systems. Birds have special air sacs for storing extra air and pumping it into the lungs. They also have a relatively large heart and a rapid heart rate. These adaptations keep plenty of oxygenated blood circulating to the flight muscles. Q: Birds have a relatively large heart and a rapid what? Choices: - lifespan - blink rate - digestive process - heart rate A:

Ans:
heart rate
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