Problem: Sichuan:

Qin armies finished their conquest of the kingdoms of Shu and Ba by 316 BC. Any written records and civil achievements of earlier kingdoms were destroyed. Qin administrators introduced improved agricultural technology. Li Bing, engineered the Dujiangyan irrigation system to control the Min River, a major tributary of the Yangtze. This innovative hydraulic system was composed of movable weirs which could be adjusted for high or low water flow according to the season, to either provide irrigation or prevent floods. The increased agricultural output and taxes made the area a source of provisions and men for Qin's unification of China.

Who began their conquest of Shu and Ba in 316 BC?
---
A: unanswerable

Problem: Pharmaceutical industry:

Some of these estimates also take into account the opportunity cost of investing capital many years before revenues are realized (see Time-value of money). Because of the very long time needed for discovery, development, and approval of pharmaceuticals, these costs can accumulate to nearly half the total expense. A direct consequence within the pharmaceutical industry value chain is that major pharmaceutical multinationals tend to increasingly outsource risks related to fundamental research, which somewhat reshapes the industry ecosystem with biotechnology companies playing an increasingly important role, and overall strategies being redefined accordingly. Some approved drugs, such as those based on re-formulation of an existing active ingredient (also referred to as Line-extensions) are much less expensive to develop.

What accounts for nearly half of the costs to develop drugs?
---
A: opportunity cost of investing capital

Problem: Annelid:

Annelids with blood vessels use metanephridia to remove soluble waste products, while those without use protonephridia. Both of these systems use a two-stage filtration process, in which fluid and waste products are first extracted and these are filtered again to re-absorb any re-usable materials while dumping toxic and spent materials as urine. The difference is that protonephridia combine both filtration stages in the same organ, while metanephridia perform only the second filtration and rely on other mechanisms for the first in annelids special filter cells in the walls of the blood vessels let fluids and other small molecules pass into the coelomic fluid, where it circulates to the metanephridia. In annelids the points at which fluid enters the protonephridia or metanephridia are on the forward side of a septum while the second-stage filter and the nephridiopore (exit opening in the body wall) are in the following segment. As a result, the hindmost segment (before the growth zone and pygidium) has no structure that extracts its wastes, as there is no following segment to filter and discharge them, while the first segment contains an extraction structure that passes wastes to the second, but does not contain the structures that re-filter and discharge urine.

What do annelids without blood vessels do to increase waste?
---
A: unanswerable

Problem: Philadelphia:

Under the Koppen climate classification, Philadelphia falls in the northern periphery of the humid subtropical climate zone (Koppen Cfa). Summers are typically hot and muggy, fall and spring are generally mild, and winter is cold. Snowfall is highly variable, with some winters bringing only light snow and others bringing several major snowstorms, with the normal seasonal snowfall standing at 22.4 in (57 cm); snow in November or April is rare, and a sustained snow cover is rare. Precipitation is generally spread throughout the year, with eight to twelve wet days per month, at an average annual rate of 41.5 inches (1,050 mm), but historically ranging from 29.31 in (744 mm) in 1922 to 64.33 in (1,634 mm) in 2011. The most rain recorded in one day occurred on July 28, 2013, when 8.02 in (204 mm) fell at Philadelphia International Airport.

What is the most rain in one day?
---
A:
8.02 in