"三凹征"
参考答案：
"三凹征"指呼吸时吸气过程显著困难，重者可出现胸骨上窝、锁骨上窝和肋间隙明显凹陷。
He runs fast nobody can catch up with him.
A．too; to
B．so; that
C．such; that
D．enough; to
高压闸阀检修质量标准是什么？
