Many plants and animals disappear abruptly from the fossil record as one moves from layers of rock documenting the end of the Cretaceous up into rocks representing the...【详情】【我要提问】
Accustomed though we are to speaking of the films made before 1927 as “silent”,the film has never been,in the full sense of the word, silent. (倒装accustomed though we...【详情】【我要提问】
The largest later named Pueblo Bonito(Pretty Town)by the Spanish, rose in five terraced stories,contained more than 800 rooms,and could have housed a population of 1,000 or ...【详情】【我要提问】
The principal elements in behavioral thermoregulation are basking (heliothermy),heat exchange with substrates such as rock or earth (thigmothermy),and diurnal and annual...【详情】【我要提问】