QUES: An example of mutual symbiosis is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones. The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish protects it from the stinging tentacles.
What lives with Ritteri sea anemones?

ANS: ocellaris clownfish

QUES: By 1988, industry observers stated that the NES's popularity had grown so quickly that the market for Nintendo cartridges was larger than that for all home computer software. Compute! reported in 1989 that Nintendo had sold seven million NES systems in 1988, almost as many as the number of Commodore 64s sold in its first five years. "Computer game makers [are] scared stiff", the magazine said, stating that Nintendo's popularity caused most competitors to have poor sales during the previous Christmas and resulted in serious financial problems for some.
When did Compute! report the number of systems sold at 7 million?

ANS: 1989

QUES: The quality of a vacuum is indicated by the amount of matter remaining in the system, so that a high quality vacuum is one with very little matter left in it. Vacuum is primarily measured by its absolute pressure, but a complete characterization requires further parameters, such as temperature and chemical composition. One of the most important parameters is the mean free path (MFP) of residual gases, which indicates the average distance that molecules will travel between collisions with each other. As the gas density decreases, the MFP increases, and when the MFP is longer than the chamber, pump, spacecraft, or other objects present, the continuum assumptions of fluid mechanics do not apply. This vacuum state is called high vacuum, and the study of fluid flows in this regime is called particle gas dynamics. The MFP of air at atmospheric pressure is very short, 70 nm, but at 100 mPa (~6997100000000000000♠1×10−3 Torr) the MFP of room temperature air is roughly 100 mm, which is on the order of everyday objects such as vacuum tubes. The Crookes radiometer turns when the MFP is larger than the size of the vanes.
What is the study of residual gases in a spacecraft called?

ANS: unanswerable

QUES: A residential elevator is often permitted to be of lower cost and complexity than full commercial elevators. They may have unique design characteristics suited for home furnishings, such as hinged wooden shaft-access doors rather than the typical metal sliding doors of commercial elevators. Construction may be less robust than in commercial designs with shorter maintenance periods, but safety systems such as locks on shaft access doors, fall arrestors, and emergency phones must still be present in the event of malfunction.
What type of elevators are generally less costly than full commercial elevators?

ANS:
residential