乙肝和（）的传播途径是一样的？
A.艾滋病
B.甲肝
C.乙脑
D.流感
参考答案：A
I had _________ entered the classroom when I noticed the headmaster was sitting at the back.
A．still
B．yet
C．sooner
D．hardly
在控制燃烧时，需将可燃物的温度降至其( )以下。
A．闪点B．燃电C．自燃点D．着火点
