焊补燃料容器和管道的常用安全措施有两种,称为:()
A、置换焊补
B、带压置换焊补
C、带压不置换焊补
D、大电流焊补
E、带料焊补
参考答案:A, C
请完善程序(程序文件名:Java_3.java)并进行调试。请在下画线处填入正确内容,然后删除下画线。请勿删除注释行和其他已有的语句内容。 [题目要求] 统计一个英文文本字符串包含的英文元音字母的个数,使程序的运行结果如下: The text contained vowels:88 源程序:public class Java_3 public static void main(String[] args) String text = " Beijing, the Capital City, is the political, "+ "cultural and diplomatic centre of China. It has"+ "become a modern international cosmopolitan city"+ " with more than 11 million people. The Capital"+ " International Airport, 23.5 km from the city centre,"+ "is China’s largest and most advanced airport. " ; int vowels =0; int (1) = text.length(); for(int i = 0;i<textLength; i++) char ch=Character.toLowerCase( text. (2) ); if(ch==’a’||ch==’e’||ch==’i’||ch==’o’||ch==’u’) (3) ; System.out.println( "The text contained vowels:" + vowels +"\n");
树脂被铁污染的现象有哪些?