卫氏并殖吸虫的第二中间宿主是()
A．海蟹
B．野猪
C．川卷螺
D．蛄
E．以上均不是
参考答案：D
-_____________can we board our plane?
-In twenty minutes. [ ]
A. How soon
B. How long
C. How often
子宫内膜有何特点？
