月经量增多或经期延长，但周期基本正常，应考虑为（）。
A.子宫肌瘤
B.子宫内膜癌
C.宫颈癌
D.宫颈息肉
E.无排卵型功能失调性子宫出血
参考答案：A
The magician picked several persons ______ from the audience and asked them to help him with the performance.
A．by accident
B．at random
C．on occasion
D．on average
什么叫粒度分析曲线？它有何作用？
