题目内容
More bison were killed．The bison population is thought ______ from 60 million to just a few hundred between 1850 and 1910.
|
A．to have fallen |
B．having fallen |
|
C．to fall |
D．falling |
【答案】
A
【解析】略
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More bison were killed．The bison population is thought ______ from 60 million to just a few hundred between 1850 and 1910.
| A．to have fallen | B．having fallen |
| C．to fall | D．falling |