礼貌用语有八类之多，而“不必客气，这是我应该做的”这一句，应该属于道歉语类。（）
参考答案：错
—You part in the party in time.
—Sorry，I was delayed by the accident.
A．are supposed to take
B．have supposed to take
C．are supposed to have taken
D．supposed to take
在完全竞争的市场中，行业的长期供给曲线取决于 ( )
A．SAC曲线最低点的轨迹
B．SMC曲线最低点的轨迹
C．LAC曲线最低点的轨迹
D．LMC曲线最低点的轨迹
