[单项选择]Paleoanthropologists examine fossil remains of extinct primates, while physical anthropologists concernwith ethnology study the behavior of primates intheir natural settings.

[单项选择]

The fossil remains of the first flying vertebrates, the pterosaurs, have intrigued paleontologists for more than two centuries. How such large creatures, which weighed in some cases as much as a piloted hang-glider and had wingspans from 8 to 12 meters, solved the problems of powered flight, and exactly what these creatures were—reptiles or birds—are among the questions scientists have puzzled over.
Perhaps the least controversial assertion about the pterosaurs is that they were reptiles. Their skulls, pelvises, and hind feet are reptilian. The anatomy of their wings suggests that they did not e- valve into the class of birds. In pterosaurs a greatly elongated fourth finger of each forelimb supported a wing like membrane. The other fingers were short and reptilian, with sharp claws. In birds the second finger is the principal strut of the wing, which consists primarily of feathers. If the pterosaurs walked on all fours, the three short fingers may have been em
A. revolutionary
B. unlikely
C. unassailable
D. probable

[单项选择]There are fossil remains of dinosaurs In the rocky strata of every continent.


A. layers
B. areas
C. peaks
D. canyons

[单项选择]There are fossil remains of dinosaurs in the rocky strata of every continent.


A. layers
B. areas
C. peaks
D. canyons

[单项选择]What is the specific feature of fossil fuels


A. They are colorless.
B. They are odorless.
C. They are rich in carbon.
D. They are easy to freeze.

[单项选择]According to the text, fossil studies of radiolaria are significant because they.


A. live in the depths of the ocean
B. are one-celled
C. have survived through the ages
D. demonstrates climatic changes prior to humans

[单项选择]The discovery of dinosaur fossil sites in Bolivia is eciting because of the following reasons ECEPT______.


A. they are found in a continent other than Asia and North Continent.
B. the largest dinosaurs in the world are found in this discovery.
C. there are some unknown species of dinosaurs found this time.
D. the dinosaurs were believed to be some of the last ones on eart