The following code:
var str= \"English Comprehension<\\/strong>
JavaScript doesn't allow literal line breaks in strings unless you escape them with \:
var str= "English Comprehension<\/strong>\
\
\
- Synonyms/Antonyms/Word Meaning (Vocabulary)<\/li>\
- Complete the Sentence (Grammar)<\/li>\
- Spot error/Correct sentence (Grammar/sentence construction)<\/li>\
- Sentence Ordering (Comprehension skills)<\/li>\
- Questions based on passage (Comprehension skills)<\/li>\
<\/ul>\
";
You might look at ES2015+ template literals instead, which use backticks instead of ' or " and allow literal line breaks:
var str= `English Comprehension<\/strong>
- Synonyms/Antonyms/Word Meaning (Vocabulary)<\/li>
- Complete the Sentence (Grammar)<\/li>
- Spot error/Correct sentence (Grammar/sentence construction)<\/li>
- Sentence Ordering (Comprehension skills)<\/li>
- Questions based on passage (Comprehension skills)<\/li>
<\/ul>
`;
But of course, that only works on ES2015-compatible JavaScript engines (or if you transpile).
Note that within a template literal ${...} has special meaning (allowing you to substitute the result of any expression:
let v = "Ma";
console.log(`Look ${v}, no hands!`); // Look Ma, no hands!