语法填空。

     阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或

使用括号中词语的正确形式填空。

     When very small dinosaur bones were found in a German mine, people thought they were from baby

dinosaurs. 1______ scientist Martin Sander's work shows that they were probably fully 2______ (grow)

and belong to the smallest giant dinosaur species ever found.

     Growth marks on dinosaur bones are similar 3______ growth rings on trees. The rings are far apart

while the animalis young and growing quickly. 4______ get closer as growth slows. "It is 5______ (exact)

these tight ring marks that we found in the fossil (化石) bones," says Sander. So the fossils must have been

from adult animals. 

     6______ was this German dinosaur so much smaller than other giant dinosaurs, which grew up to 45

metres long and weighed as much as a thousand humans?

     150 million years ago, most of Germany was underwater. Scientists think that 7______ water levels rose,

there was less and less land and food available. The dinosaur 8______ (force) to adapt and evolved into a

smaller animal 9______ (need) less space and food.

     Since 1998, scientists have dug up more than 1000 dinosaur fossils in the mine. It is one of the few places

in the world 10______ the bones and footprints of dinosaurs have been found together.