A set of JavaScript multiple-choice questions has P4 answers

Please read your knowledge and multiple choice questions around the JavaScript topic that the Network Administrator has edited below. The set of questions includes 10 sentences to try.

Question 1. When does the Onchange event JavaScript happen?
1. When an object in the form receives focus
2. Occurs when the value of a field in the form is changed by the user
3. When an object in form loses focus
4. When you click your mouse on the command button
Question 2. How to add a multi-line comment in JavaScript?
1. / * This is a comment on many lines * /
3. // This is a comment on many lines //
Question 3. When does the Onload event JavaScript happen?
1. When starting the program
2. When you click
3. At the end of a program
4. When hovering over
Question 4. Is JavaScript language case-sensitive?
1. Have
2. Is not
Question 5. How can I know if the browser is being used at the client?
1. navigator.appName
2. browser.name
3. client.navName
Question 6. Which of the following statements correctly calls an external script named 'xxx.js'?