若某商品价格上升2%，其需求量下降10%，则该商品的需求（）
A.缺乏弹性
B.富有弹性
C.具有单位弹性
D.完全无弹性
参考答案：B
— Jack said the paper was too hard when he was asked why he failed the exam again..
— Well, _____.
A．a bad penny always turns up
B．a bad workman always blames his tools
C．an early bird catches the worm
D．an apple a day keeps the doctor away
受众在大众传播中有何重要作用？
