Carcass wrote:
Churchill conceded that Russia, (i) _________ an ally of France and Great Britain, was in fact (ii) _________ to their security, but argued that Russian national interest would compel it to make (iii) _________ with those countries.
Blank i | Blank ii | Blank iii |
a) steadfastly | d) pledged | g) common cause |
b) nominally | e) indifferent | h) rack and ruin |
c) sporadically | f) immune | i) vim and vigor |
The phrase "was in fact" suggests that there is a contradiction between the kind of ally Russia was (appearance) and its consequence to the national security of France and Great Britain (actual fact). Thus, the words we choose for the first and second blanks should reflect this contradiction.
We can right away rule out
steadfastly because we know that it was an appearance.
We can choose
nominally because it means something that is in name only; something that is officially though perhaps not in reality - or in other words
an appearance.
Well if Russia was nominally an ally then the second blank should be a word that indicates the reality, which is contradictory to it being an ally, and therefore the word
indifferent is the best choice.
Churchill conceded that Russia, (i)
nominally an ally of France and Great Britain, was in fact (ii)
indifferent to their security
The "but" after the comma indicates a new idea that is in contradiction to the earlier sentence fragment, which states that Russia was indifferent to the security concerns of France and Great Britain. Well then the second part of the sentence should assert the opposite - namely, Russian national interest would compel it to make
common cause with those countries.
"to make vim and vigor with those countries" is wrong and bad usage.
Coming back to the first blank,
If we say "sporadically an ally" we would have to choose "pledged to their security", in which case the third blank would have to be filled with a word which means "discord with those countries". But no option that is a synonym of "discord" is available which makes good sense from the point of view of grammar and usage. Of course "rack and ruin" is a synonym of discord but "to make and ruin with those countries" is bad usage, in fact wrong usage. But "to make common cause" is accepted usage, a common expression used regularly and fits in perfectly.
So we are justified in eliminating "sporadically" for the first blank.