QUES: The armillary sphere, a three-dimensional representation of the movements in the celestial sphere, was invented in Han China by the 1st century BC. Using a water clock, waterwheel and a series of gears, the Court Astronomer Zhang Heng (78–139 AD) was able to mechanically rotate his metal-ringed armillary sphere. To address the problem of slowed timekeeping in the pressure head of the inflow water clock, Zhang was the first in China to install an additional tank between the reservoir and inflow vessel. Zhang also invented a seismometer (Houfeng didong yi 候风地动仪) in 132 AD to detect the exact cardinal or ordinal direction of earthquakes from hundreds of kilometers away. This employed an inverted pendulum that, when disturbed by ground tremors, would trigger a set of gears that dropped a metal ball from one of eight dragon mouths (representing all eight directions) into a metal toad's mouth.
What was exchanged from mouth to mouth in the usage of the seismometer?

ANS: metal ball

QUES: In species which show a distinct difference between heartwood and sapwood the natural color of heartwood is usually darker than that of the sapwood, and very frequently the contrast is conspicuous (see section of yew log above). This is produced by deposits in the heartwood of chemical substances, so that a dramatic color difference does not mean a dramatic difference in the mechanical properties of heartwood and sapwood, although there may be a dramatic chemical difference.
Is the color difference between heartwood and sapwood usually very subtle or conspicuous?

ANS: conspicuous

QUES: The word "public" implies the highest level of inclusivity – the public sphere by definition should be open to all. However, this sphere was only public to relative degrees. Enlightenment thinkers frequently contrasted their conception of the "public" with that of the people: Condorcet contrasted "opinion" with populace, Marmontel "the opinion of men of letters" with "the opinion of the multitude," and d'Alembert the "truly enlightened public" with "the blind and noisy multitude". Additionally, most institutions of the public sphere excluded both women and the lower classes. Cross-class influences occurred through noble and lower class participation in areas such as the coffeehouses and the Masonic lodges.
Marmontel contrasted "the opinion of men of letters" with what?

ANS: "the opinion of the multitude,"

QUES: Among the challenges being faced to improve the efficiency of LED-based white light sources is the development of more efficient phosphors. As of 2010, the most efficient yellow phosphor is still the YAG phosphor, with less than 10% Stoke shift loss. Losses attributable to internal optical losses due to re-absorption in the LED chip and in the LED packaging itself account typically for another 10% to 30% of efficiency loss. Currently, in the area of phosphor LED development, much effort is being spent on optimizing these devices to higher light output and higher operation temperatures. For instance, the efficiency can be raised by adapting better package design or by using a more suitable type of phosphor. Conformal coating process is frequently used to address the issue of varying phosphor thickness.
 What is the percentage of stoke shift loss in non-YAG phosphor?

ANS:
unanswerable