气电立焊时，不是焊瘤产生的原因是（）
A.铜垫板没有对中
B.铜垫板的槽过宽
C.铜垫板与母材间有较大的间隙
D.保护气体流量过大
参考答案：D
Chinese President Hu Jintao had had _____ brief meeting with three astronauts who were going board _____
country's third manned spacecraft Shenzhou VII on Sept 25. 2008. [ ]
A. the; a
B. a; a
C. a; the
D. the ; the
门诊麻醉用咪达唑仑可预防气管插管时的眼压升高。
