6. As air-breathing mammals. Whales must once have lived on land and needed hind limbs capable of supporting the mammals' weight. Whales have the bare remnants of a pelvis. If animals have a pelvis, we expect them to have hind limbs. A newly discovered fossilized whale skeleton has very fragile hind limbs that could not have supported the animal's weight on land. This skeleton had a partial pelvis.
If the statement above are true, which one of the following, if also true, would most strongly support the conclusion that the fragile hind limbs are remnants of limbs that land-dwelling whales once had?
(A) Whale bones older than the fossilized hind limbs confirm that ancient whales had full pelvises.
(B) No skeletons of ancient whales with intact hind limbs capable of supporting the mammals' weight have ever been found.
(C) Scientists are uncertain whether the apparently nonfunctioning limbs of other early mammals derived from once-functioning limbs of their ancestors.
(D) Other large-bodied mammals like seals and sea lions maneuver on beaches and rocky coasts without fully functioning hind limbs.
(E) Some smaller sea-dwelling mammals. Such as modern dolphins. Have no visible indications of hind limbs
为什么答案是A?????
25. Situation: In the island nation of Bezun ,the government taxes gasoline heavily in order to induce people not to drive . It uses the revenue from the gasoline tax to subsidize electricity in order to reduce prices charged for electricity.
Analysis: The greater the success achieved in meeting the first of these objectives, the less will be the success achieved in meeting the second .
The analysis provided for the situation above would be most appropriate in which one of the following situations?
(A) A library charges a late fee in order to induce borrowers to return books promptly. The library uses revenue from the late fee to send reminders to tardy borrowers on order to reduce the incidence of overdue books .
(B) A mail-order store imposes a stiff surcharge for overnight delivery in order to limit use of this option. The store uses revenue from the surcharge to pay the extra expenses it incurs for providing the overnight delivery service.
(C) The park management charges an admission fee so that a park's users will contribute to the park's upkeep. In order to keep admission fees low ,the management does mot finance any new projects from them.
(D) A restaurant adds a service charge in order to spare customers the trouble of individual tips. The service charge is then shared among the restaurant's workers in order to augment their low hourly wages.
(E) The highway administration charges a toll for crossing a bridge in order to get motorists to use other routes .It uses the revenue from that toll to generate a reserve fund in order to be able one day to build a new bridge.
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