Tag: science & technology

In classic Internet Explorer and Windows Explorer, ALT+O opens the Favorites menu. ALT+F opens the File menu, ALT+V opens View menu, and ALT+F4 closes the application entirely.

Mercury is the only metal that is liquid at room temperature, with a melting point of approximately -38.83°C. This unique physical property makes it easily distinguishable from other metals. Option B is correct despite the typo.

Sirius has the highest apparent magnitude (brightness as seen from Earth) of any star in the night sky at -1.46. While the Sun is brighter overall, Sirius is the brightest star beyond our solar system. The other options are incorrect: Einstein did not discover stars, no star stays fixed above the North Pole (Polaris does), and stars do not make sounds detectable by radio telescopes.

Sharks are cartilaginous fish, meaning their skeleton is made of cartilage rather than bone. This makes them lighter and more flexible than bony fish. Sharks definitely have teeth (multiple rows), gills for breathing, and the option 'lever' appears to be a typo or irrelevant.

Smog is a portmanteau word formed from 'smoke' and 'fog'. It refers to a type of air pollution typically caused by exhaust emissions from vehicles and industrial smoke mixing with fog. Option C is just a playful backronym, and option D is a nonsensical chemical formula.

Ozone (O3) is a powerful oxidizing agent used in water treatment to kill bacteria, viruses, and other microorganisms. It is more effective than chlorine for some pathogens and leaves no harmful residues. Oxygen (O2) and carbon dioxide (CO2) are not used for purification, and ammonia (NH3) is sometimes used in water treatment but primarily for pH adjustment, not purification.

Schizophrenia is a chronic mental disorder affecting thinking, feeling, and behavior. It is not a bone disease, brain tumor, or blood cancer. Symptoms include hallucinations, delusions, and disorganized thinking.

Humans require 9 essential amino acids that cannot be synthesized by the body and must be obtained from diet: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The other numbers are incorrect.

Hematological malignancies are cancers of the blood, bone marrow, and lymph nodes, including leukemia, lymphoma, and myeloma. 'Blood Cancer' is the correct term. It is not an STD, liver dysfunction, or vascular blockage.

Methanol (CH3OH) is historically called 'wood alcohol' because it was originally produced by destructive distillation of wood. It is not fruit alcohol, anesthesia, or 'none of the above'. It is toxic and used as an industrial solvent and fuel.