Problem: One of the most complex characters found in modern Chinese dictionaries[g] is (U+9F49) (nang, listen (helpinfo), pictured below, middle image), meaning "snuffle" (that is, a pronunciation marred by a blocked nose), with "just" thirty-six strokes. However, this is not in common use. The most complex character that can be input using the Microsoft New Phonetic IME 2002a for traditional Chinese is (da, "the appearance of a dragon flying"). It is composed of the dragon radical represented three times, for a total of 16 3 = 48 strokes. Among the most complex characters in modern dictionaries and also in frequent modern use are (yu, "to implore"), with 32 strokes; (yu, "luxuriant, lush; gloomy"), with 29 strokes, as in (youyu, "depressed"); (yan, "colorful"), with 28 strokes; and (xin, "quarrel"), with 25 strokes, as in (tiaoxin, "to pick a fight"). Also in occasional modern use is (xian "fresh"; variant of xian) with 33 strokes.
What are among the most complex characters in modern dictionaries?
The answer is the following: yu

Problem: Chapter XI deals with evidence from biogeography, starting with the observation that differences in flora and fauna from separate regions cannot be explained by environmental differences alone; South America, Africa, and Australia all have regions with similar climates at similar latitudes, but those regions have very different plants and animals. The species found in one area of a continent are more closely allied with species found in other regions of that same continent than to species found on other continents. Darwin noted that barriers to migration played an important role in the differences between the species of different regions. The coastal sea life of the Atlantic and Pacific sides of Central America had almost no species in common even though the Isthmus of Panama was only a few miles wide. His explanation was a combination of migration and descent with modification. He went on to say: "On this principle of inheritance with modification, we can understand how it is that sections of genera, whole genera, and even families are confined to the same areas, as is so commonly and notoriously the case." Darwin explained how a volcanic island formed a few hundred miles from a continent might be colonised by a few species from that continent. These species would become modified over time, but would still be related to species found on the continent, and Darwin observed that this was a common pattern. Darwin discussed ways that species could be dispersed across oceans to colonise islands, many of which he had investigated experimentally.
Why couldn't differences in flora and fauna be explained by differences in regions alone?
The answer is the following: South America, Africa, and Australia all have regions with similar climates at similar latitudes, but those regions have very different plants and animals

Problem: Reptiles such as adders and vipers live up to the snow line; because they cannot bear the cold temperatures they hibernate underground and soak up the warmth on rocky ledges. The high-altitude Alpine salamanders have adapted to living above the snow line by giving birth to fully developed young rather than laying eggs. Brown trout can be found in the streams up to the snow line. Molluscs such as the wood snail live up the snow line. Popularly gathered as food, the snails are now protected.
What can be found in the streams up to the snow line?
The answer is the following: Brown trout

Problem: Antibacterial antibiotics are commonly classified based on their mechanism of action, chemical structure, or spectrum of activity. Most target bacterial functions or growth processes. Those that target the bacterial cell wall (penicillins and cephalosporins) or the cell membrane (polymyxins), or interfere with essential bacterial enzymes (rifamycins, lipiarmycins, quinolones, and sulfonamides) have bactericidal activities. Those that target protein synthesis (macrolides, lincosamides and tetracyclines) are usually bacteriostatic (with the exception of bactericidal aminoglycosides). Further categorization is based on their target specificity. "Narrow-spectrum" antibacterial antibiotics target specific types of bacteria, such as Gram-negative or Gram-positive bacteria, whereas broad-spectrum antibiotics affect a wide range of bacteria. Following a 40-year hiatus in discovering new classes of antibacterial compounds, four new classes of antibacterial antibiotics have been brought into clinical use in the late 2000s and early 2010s: cyclic lipopeptides (such as daptomycin), glycylcyclines (such as tigecycline), oxazolidinones (such as linezolid), and lipiarmycins (such as fidaxomicin).
How many new classes of antibacterial antibiotics was introduced in the late 2000's/
The answer is the following:
four