(B) Produces lower quality products
(C) Higher cost
(D) Uses less space
42. In line 27, the word "uptake" is closest in meaning to
(A) allowance
(B) rising
(C) absorption
(D) respiration
Questions 43-50
Whereas most animal teeth, including those of the odontocetes whales, are made of tough rock-like calcium, the mouths of the mystecetes whales are lined with a series of vertical, blade-like plates which hang from the upper jaw enabling them to filter their food from the seawater. Made from keratin, the same material found in fingernails, these food gathering combs are collectively referred to as a baleen. The whales fill their mouths with tons of seawater and then strain the collected mass through the baleen mats to estract tiny crustaceans such as krill, copepods and the occasional very small fish. Despite their large size, these whales have an esophagus of only a few inches in diameter which prohibits them from swallowing anything much larger than the smallest sardines. Instead of hunting for their prey, the baleen whales merely propel themselves through the fertile surface waters collecting the abundant material in their filtering apparatus.
The odontocetes, or toothed whales, have peg-like teeth which grasp prey but do not chew it, and their throats are large enough to devour entire squids, octopus and small sharks. Under ideal conditions, they feed opportunistically upon whatever is immediately available though they are capable of diving over a half mile deep in pursuit of food. As the feeding grounds of the odontocetes vary seasonally according to the availability of prey, they typically must migrae long distances.
While both the toothless mystecetes and the carnivorous odontocetes have similar physical characteristics, including an average overall isze exceeding twenty meters and a shared mammalian background, their habitats and behaviors differ due to their distinct nutritional needs. An interesting distinction is the lack of social behaviors among the toothless animals. Herding behavior demonstrates the rule among toothed whales as opposed to the baleen whales which typically travel in pairs or individually, believed to use a primitive form of communication among their peers as an aid in pursiung food.
43. what is the main topic of the passage?
(A) the difference between toothed and toothless whales.
(B) The behavior of whales
(C) The nutritional requirements for whales
(D) The physical characteristics of whales
44. Accoridng to the pasage, the mystecetes can be differentiated from odontocetes by
(A) the presence of teeth
(B) The presence of baleen
(C) a mammalian background
(D) large body size
45. Which of the following is NOT consumed by mystecetes whales?
(A) Krill
(B) Copepods
(C) Sardines
(D) Squids
46. It line 8, the word "esophagus" is closest in meaning to
(A) baleen
(B)teeth
(C)throat
(D) brain
47. Which of the following is NOT mentioned as a food source for odontocetes?
(A) Squids
(B) Sharks
(C) Krill
(D) Octopus
48. How frequently od the odontocetes need to migrate in search of food?
(A) Once a year
(B) As the seasons chane
(C) Every month
(D) Occasionally
49. Accoridng to the author, what helps explain mystecetes relatively undeveloped communication?
(A) They have large nutritional requirements.
(B) They do not need to hunt for food.
(C) they are too large.
(D) Their esophagus is too small.
50. Which of the following is a similarity between the mystecetes and the odontocetes?
(A) Sources of nutrition
(B) Communicative abilities
(C) Group behavior
(D) Mammalian background

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