Read the paragraph carefully and then identify which word has been replaced from which blank. The list of words has been provided below.
Nadal's game — founded on heavy topspin and great reserves of strength and patience — is ideal for a surface with a slow and high bounce. Of course, he is so much more than a clay court wonder. His career has been marked by a __1__ that has seen him come to grips with different surfaces. Those who believed his game was unsuited for grass, which plays fast and low, had to eat their words as his gradual __2__ on the surface yielded two Wimbledon titles. His performance on hard courts has been pretty impressive as well and his record of having won all four Grand Slams is proof of his all-court ability. With 11 Grand Slams under his belt, Nadal has already shown he is one of the greats of the modern era. His game is built around an astonishing fleetness of foot, an uncanny instinct for anticipation and retrieval, a strenuously unorthodox style that delivers a huge package of power, and the patience and intensity to wear down and __3__ his opponent. For years now, some commentators have claimed that his style of play — marked by over-exertion — is programmed for injury-inflicted __4__. His somewhat off-colour performance last year was regarded by some as proof of their __5__ predictions. But the Spaniard has again shown that he cannot be written off lightly. And that you can never underestimate the power of perseverance and __6__.
A) Dishearten, B) dire, C) resilience, D) doggedness,
E) breakdown, F) improvement