TASK DEFINITION: In this task, you are given two sentences in the English language (Sentence 1 and Sentence 2). Your task is to identify the connecting word between the two sentences.
PROBLEM: Sentence 1:Anand , the tournament 's hitherto - untroubled No. 1 seed , breezed through the quarterfinal round against his longtime rival Vassily Ivanchuk . Sentence 2:But Boris Gelfand gave Anand a challenge in the semi-final , and the match was not settled until a sudden - death blitz game .

SOLUTION: but

PROBLEM: Sentence 1:In the position at left , White to play will apparently be obliged to retreat the knight from f5 , because the squares to which it could advance are all guarded . Sentence 2:However , the interference move 1. Nd6+ interrupts the black rook 's defense of the black queen .

SOLUTION: however

PROBLEM: Sentence 1:This book became the subject of legal action due to copyright issues . Sentence 2:However , the issues were ruled against , and the book continues to be sold .

SOLUTION:
however