How to convert from Buffer instance to string of base64? 

Which of the following code print the total free memory of operating system?

Select valid stream instances:

How can you access the command line arguments passed to your program?

Which of the following is the correct way to get a normalized path? 

What is the output in console of this code? var events = require('events'); var myEventEmitter = new events.EventEmitter(); myEventEmitter.once('a', function () { console.log('a')}); myEventEmitter.on('b', function () { console.log('b')}); myEventEmitter.emit('a'); myEventEmitter.emit('b'); myEventEmitter.emit('a'); myEventEmitter.emit('b');

Which of the following should not to use in NodeJS?

Which of the following is the result of module.id ?

Which of the following timers methods exists in Node.js?

Which of the following variables you can use in modules?

Which of the following classes is the parent for repl.REPLServer class?