睾丸鞘膜积液的特征是（）
A.阴囊肿块有明显的红肿热痛
B.透光试验阴性
C.透光试验阳性
D.均质的实质性肿块
E.阴囊肿块可闻及肠鸣音
参考答案：C
—What’s wrong with you, Ann?
—My mother is ill. I have to her at home.
A．look at
B．look for
C．look after
D．look around
标准CD光盘容量为（）
A.600MB
B.640MB
C.680MB
D.700MB
