三峡水电站每小时大约能发电 一百二十万九千七百千瓦．
写作：______．
一百二十万九千七百写作：1209700；
故答案为：1209700．
一个自然生态系统中，肉食性动物总比植食性动物的数量 。（选填“多”或“少”）
In western culture,21 was the age________ young people traditionally received a key to their parents’ door, as a symbol of entering adulthood.
A．in which
B．on which
C．at which
D．to which
