市场上商品供不应求，价格上涨；供过于求，价格下降。所以，价格是由供求关系决定的。 ( )
参考答案：错
123.To his surprise, his speech at the meeting ________ the students silent.
A．caught
B．took
C．held
D．Keep
We were________the most important scientific development of the century.[ ]
A. seeing
B. watching
C. looking
D. witnessing
