For the following seven questions - Choose and write the word what is equivalent in meaning to the underline word/s.
He will not change his opinion, since he is very obstinate:
In his thirties, he was at the utmost height of his career.
He was rather presumptuous in his behaviour.
When he saw the results, his ecstasy knew no bounds:
The fear he felt them was intense:
For the following four questions - Fill in the blanks by choosing the correct alternative.
He failed ________ his best efforts.