下机纬密
参考答案:指织物了机后所测量的单位长度内的纬纱根数。
My friend’s flight had taken off _________ I got to the airport to see him off.
A.while
B.after
C.before
D.until
急性一氧化碳中毒时,最先受损的脏器为( )
A.心和肺
B.心和脑
C.肺和脑
D.肺和肾