以x轴为准线,F(-1,-4)为焦点的抛物线方程
顶点坐标(-1,-2),P=4,所以抛物线方程
I’m sorry to tell you that the library doesn’t allow ________ loudly.
A.talking
B.to talk
C.anyone talking
D.anyone talk
男,18岁,左侧阴囊有坠胀感,可扪及蚯蚓状团块,平卧后团块缩小,最可能的诊断是
A.原发性精索静脉曲张
B.继发性静脉曲张
C.睾丸鞘膜积液
D.附睾结核
E.斜疝