梅毒的唯一传染源是（）
A.猫
B.人
C.鼠
D.蚤
E.蚊
参考答案：B
解析：梅毒螺旋体只感染人，人是梅毒的惟一感染源。
—Do you know _________ the meeting?
—Tomorrow morning.
A．when they had
B．when they are going to have
C．when did they have
D．when are they going to have
