市场竞争不够充分、价格相对偏高的品种
A．加大降价力度B．适当提高价格C．少降价格D．维持价格E．少降或维持价格
参考答案：A
管道结蜡会使管道输油（）.
A.摩阻变小
B.压力降低
C.能力下降
D.温度下降
—Could you let me know ______ yesterday?
—Because the traffic was heavy. [ ]
A. why did you come late
B. why you came late
C. why do you come late
D. why you come late
