const poem = (

  word1_1,  

  word1_2,

  word2_1,

  word2_2,

  line3param,

  line4param

) => {

  const line1 = `${word1_1 || 'Roses'} are ${word1_2 || 'red'}.\n`;

  const line2 = `${word2_1 || 'Violets'} are ${word2_2 || 'blue'}.\n`;

  const line3 = `${line3param || 'Sugar is sweet'}.\n`;

  const line4 = `${line4param || 'And so are you'}.`;

  return line1 + line2 + line3 + line4;

}

​

​

const myPoem = poem(

  'Dandelions',

  'yellow',

  'Boogers',

  'green',

  'I\'m a nice fellow',

  'Whose nose is squeaky clean'

);

​

console.log(poem());

​

console.log(myPoem);