黑白瓶法通过测定水体中的（）浓度来测定水体的初级生产力。
参考答案：O2
75个桃子2个2个的装筐，不能正好装完，但3个3个的装，5个5个的装都能正好装完。[ ]
The topic, which many people ______ a small one, will actually have a great influence _____ us.
A．think as; to
B．think of as; on
C．think as; upon
D．think of as; to
