气管下段异物病人呼吸困难严重，为挽救病人生命，应立即做气管切开手术。
参考答案：错
.------What can I do for you?
------I’d like to have the film____. How much is it?
A developed B.washed C.taken D.made
“背斜成山，向斜成谷”的主要地质作用是[ ]
A、内力作用
B、搬运作用
C、侵蚀作用
D、沉积作用
