催化剂活化过程是使再生过程中积聚的金属晶粒重新分散和补氯以提高催化剂使用性能。
参考答案:对
He told me about the news in a voice. [ ]
A. amazing; surprising
B. amazed; surprised
C. amazing; surprised
D. amazed; surprising
某井下φ56mm管式抽油泵,泵上为φ62mm油管,泵挂1600m,试压时打压10MPa。问:油管因打压产生的拉力是多少?(精确到小数点以后三位数)