钢筋骨架加工要求钢筋机械连接，宜使用什么挤压接头？
参考答案：
宜使用带肋钢筋套筒挤压接头。
--- John, where are the cookies? Don’t tell me you ate them all!
--- ______ I couldn’t help it. They were so good.
A．Yes, I did.
B．No, I didn’t.
C．Yes, I have.
D．Why? Sounds strange!
高空急流出现的高度一般在（）.
A.对流层中上部
B.对流层上部和平流层下部
C.逆温层附近
