（）是指与现有技术相比，该发明具有突出的实质性特点和显著的进步，该实用新型具有实质性特点和进步。
参考答案：创造性
I had just stepped out of the bathroom and was busily drying myself with a towel ______ I heard the steps.
A．while
B．when
C．since
D．after
有关局灶型肺结核的描述中，哪项是错误的：
A．患者常无自觉症状，常可自然痊愈B．可有干酪样坏死C．属于活动性肺结核D．病变多位于肺尖部E．多为增生性病变
