题目内容：

    Dinosaurs lived on Earth more than 60 million years（A）____________human beings. They lived（B）everywhere on Earth. Some dinosaurs were as small as chickens. （C）____________were as big as ten elephants. Some could even fly. Many dinosaurs ate plants. However, some dinosaurs liked to eat meat.

Dinosaurs lived on Earth for（D）more than 150 million years. Then, suddenly, they all died out. （E）没有人知道为什么。However, we can lean about then from（F）their fossils.

1.在（A）（C）处填入适当单词：____________, ____________

2.写出（B）和（D）的同义词语：____________, ____________

3.写出（F）处指代内容：________________________

4.将（E）处译成英语：________________________

5.写出本文的中心词；________________________