Answer:
The correct answers are:
Insistent: Not giving up.
Menacing: Threatening.
Lithe: Graceful; Agile.
Bleak: Hopeless; depressing.
Prestigious: Highly respected.
Explanation:
For this type of exercise it is always convenient that you first read all the options, and try to think if at least you know some, to reduce the others.
Once you have a few left, if you don't know its meaning, you can consult a dictionary, look for sentences that have those words and you can understand them by context, etc.
In this way it will be easier to join each word with its definition and thus learn its meaning.
