单项选择题
A．the city is so large and so high B．there is no traffic C．we don’t know the road D．the city is so large and the traffic is so heavy
A．studying dinosaur fossils B．examining modern animals C．watching dinosaurs D．using telescopes
A．lived a partly human life B．was a branch of Homo sapiens C．used tools before Homo sapiens arrived D．had a brain as large as a common chimp’s