造成原油中断的原因有哪些？
参考答案：
①原油换罐时阀门开错；
②原油罐液面过低，泵抽空；
③原油泵入口线堵、凝线或泵体故障。
He was __ with the results of the exam, which can be seen from his look .
A．satisfied, satisfying
B．satisfied, satisfied
C．satisfying, satisfied
D．satisfying, satisfying
下面程序main(){ int x=100, a=10, b=20, ok1=5, ok2=0;if(a＜b) if(b!=15) if(!ok1) x=1; else if(ok2) x=10;x=1;printf("%d\n", x);}的输出是 ______。
A．-1
B．0
C．1
D．不确定的值
