1. Electroencephalography (EEG) measures electrical activity in the brain, primarily reflecting the activity of:

A. Neurons
B. Astrocytes
C. Oligodendrocytes
D. Microglia

Correct answer: A

Rationale: The correct answer is A: Neurons. Electroencephalography (EEG) measures the electrical activity in the brain, which is primarily generated by the neurons. Neurons are the main cells responsible for transmitting electrical signals in the brain, making them the key source of the brain's electrical activity. Astrocytes, oligodendrocytes, and microglia are important supporting cells in the brain but do not generate the electrical impulses that EEG measures. Therefore, the correct choice is A: Neurons.

2. What is the absolute value of -7?

A. 49
B. 17
C. 7
D. 14

Correct answer: A

Rationale: Absolute value refers to the non-negative distance of a number from zero. Regardless of being positive or negative, 7 is its distance from zero.

3. How can you predict the charge of an ion formed by an element based on its position on the periodic table?

A. Look for elements with similar atomic weights
B. Identify the group number, which often indicates the typical ionic charge
C. Identify the group number, which often indicates the typical ionic charge
D. Analyze the element's position within the period

Correct answer: B

Rationale: The group number of an element on the periodic table often indicates the typical ionic charge it will form. Elements in the same group tend to have similar chemical properties, including the tendency to gain or lose electrons to achieve a stable electron configuration. This predictable pattern allows us to anticipate the charge of an ion formed by an element based on its position in the periodic table.

4. What are the four main types of macromolecules that are essential for life?

A. Carbohydrates, lipids, proteins, and nucleic acids
B. Carbohydrates, proteins, fats, and vitamins
C. Minerals, vitamins, proteins, and fats
D. Carbohydrates, lipids, proteins, and hormones

Correct answer: A

Rationale: These four types of macromolecules are the building blocks of life and play essential roles in various cellular processes. Carbohydrates: Carbohydrates are the primary energy source for cells and provide structural support for cell membranes and other cellular components. They are composed of carbon, hydrogen, and oxygen atoms and are classified into monosaccharides (simple sugars), disaccharides (double sugars), and polysaccharides (complex sugars). Lipids: Lipids are a diverse group of molecules that include fats, oils, and waxes. They are composed of carbon, hydrogen, and oxygen atoms and are insoluble in water but soluble in nonpolar solvents. Lipids serve as energy storage molecules, provide insulation for cells and organs, and are essential components of cell membranes. Proteins: Proteins are complex molecules composed of amino acids linked together by peptide bonds. They are responsible for a vast array of cellular functions, including structural support, enzymatic catalysis,

5. The author's attitude towards history seems to be

A. indifferent and neutral, presenting it as an objective field of study.
B. critical and dismissive, questioning its practical applicability in the present.
C. enthusiastic and optimistic, highlighting its potential to guide the future.
D. pessimistic and cautious, emphasizing the risk of repeating past mistakes.

Correct answer: C

Rationale: The passage's overall tone highlights the value and utility of history, showcasing its potential to inspire and guide us, suggesting an optimistic and encouraging view.

6. What is the function of the epiglottis?

A. Produces saliva
B. Senses taste
C. Prevents food from entering the windpipe
D. Filters blood

Correct answer: C

Rationale: Rationale: The epiglottis is a flap of cartilage located at the base of the tongue that covers the opening of the windpipe (trachea) during swallowing to prevent food and liquids from entering the airway. This action ensures that food and liquids are directed to the esophagus and down into the stomach, rather than entering the respiratory system, which could lead to choking or aspiration pneumonia. The other options (A) Produces saliva, (B) Senses taste, and (D) Filters blood are functions of other structures in the body and are not related to the role of the epiglottis.