停炉后氧气切断阀间充入氮气的目的是为了()。
A.防止氧气漏入
B.便于切断阀开关
C.向气化炉充氮
参考答案:A
动脑筋,看看下面的对话对不对,对的在括号里打“√”,错的打“×”。
( ) 1. A: What's the matter?
B: I'm fine, thank you.
( ) 2. A: How do you feel?
B: I feel sick.
( ) 3. A: Do you have an earache?
B: Thank you.
( ) 4. A: How are you?
B: I'm as good as new.
下列程序的输出结果是( ) main() { int a,b,d=25; a=d/10%9; b=a&&(-1); printf("%d,%d\n",a,b);}
A.6,1
B.2,1
C.6,0
D.2,0