state whether the underlined words are phrase or clause,give reasons​

Hello Karthika, a phrase will not have a complete form a sentence such as subject and predicate.
They earn
Here "they" is subject and earn is predicate. So it is a sentence
He arrived. He - subject and arrived predicate. So sentence
He can clear the interview easily. This too is a sentence
But in "travelling by car" is not complete having subject and predicate. So its different from above
Same way Humming a tune too is in complete
So in complete without having a form of sentence is termed as PHRASE 
And in complete sentence form is termed as CLAUSE
Hope now you can pick up clause and phrase in other cases given in your exercise work book.
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