Я думал, ____ ему есть чему радоваться.A．ч

LKJ运用区段控制参数编制软件中“长大下坡道取消常用制动”设置为开启，那么（）。

A.列车在长度大于2公里的下坡道上超速运行时，LKJ将直接发出紧急制动指令

B.列车在坡度大于20‰的下坡道上超速运行时，LKJ将直接发出紧急制动指令

C.列车在坡度大于20‰且长度大于2公里的下坡道上超速运行时，LKJ将直接发出紧急制动指令

D.列车在LKJ车载基础数据中设置为长大下坡道的区间超速运行时，LKJ将直接输出紧急制动指令

细菌和真菌在自然界中的作用是（　　）

A．它们作为分解者参与生物圈的物质循环

B．它们可以和动植物共生

C．它们可以引起动植物和人类患病

D．以上作用均有

煤气

（）不属于电工仪表技术指标

A.准确度

B.灵敏度

C.阻尼

D.偶然误差

本题的功能是用文本框来设定表盘中指针的位置。窗口中有一个画板和两个文本框，画板中绘制了一个表盘和时针、分针，通过文本框分别设定“时”和“分”，表盘中的时针和分针就会指到对应的位置上。
import java. awt. * ;
import java. awt. event. * ;
import java. awt. geom. * ;
import javax. swing. * ;
import javax. swing, event. * ;
public class java3

public static void main(String[] args)

TextTestFrame frame=new TextTestFrame();
frame. setDefaultCloseOperation (JFrame. EXIT_ON_CLOSE);
frame. show();


class TextTestFrame extends JFrame

public TextTestFrame()

setTitle("java3");
setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
Container contentPane=getContentPane();
DocumentListener listener=new DocumentListen-er();
JPanel panel=new JPanel();
hourField=new JTextField("12",3);
panel, add(hourField);
hourField, getDocument (). addDocumentListener(this);
minuteField=new JTextField("00",3);
panel, add(minuteField);
minuteField, getDocument(), addDocumentListener(listener);
contentPane, add ( panel, BorderLayout. SOUTH);
clock=new ClockPanel();
contentPane, add (clock, BorderLayout. CENTER);

public void setClock()

try

int hours
= Integer. parseInt (hourField. getText(). trim());
int minutes
= Integer. parselnt(minuteField, getText(), trim());
clock, setTime(hours, minutes);

catch (NumberFormatException e)

public static final int DEFAULT WIDTH=300;
public static final int DEFAULT_HEIGHT=300;
private JTextField hourField;
private JTextField minuteField;
private ClockPanel clock;
private class clockFieldListener extends DocumentListener

public void insertUpdate(DocumentEvent e) setClock();
public void removeUpdate(DocumentEvent e) setClock();
public void changedUpdate(DocumentEvent e)


class ClockPanel extends JPanel

public void paintComponent(Graphics g)

super, paintComponent(g);
Graphics2D g2=(Graphics2D)g;
Ellipse2D circle
=new Ellipse2D. Double(0,0,2 * RADIUS, 2 * RADIUS);
g2. draw(circle);
double hourAngle
=Math. toRadians(90-360 * minutes/(12 * 60));
drawHand (g2, hourAngle, HOUR_HAND_LENGTH);
double minuteAngle
Math. toRadians(90-360 * minutes/60)
drawHand(g2, minuteAngle, MINUTE_HAND_LENGTH);

public void drawHand(Graphics2D g2,
double angle, double handLength)

Point2D end=new Point2D. Double(
RADIUS+handLength * Math. cos(angle),
RADIUS-handLength * Math. sin(angle));
Point2D center=new Point2D. Double(RADIUS, RADIUS)
g2. draw(new Line2D. Double(center, end));

public void setTime(int h, int m)
minutes=h*60+m;
repaint();

private double minutes=0;
private double RADIUS=100;
private double MINUTE_HAND_LENGTH=0.8 * RADIUS;
private double HOUR_HAND_LENGTH=0.6 * RADIUS;