Sentence 1: Unlikely as it seems now, at one time these sugar islands were close to center stage as the great powers of Europe warred fiercely for world commercial domination.

Sentence 2: The sugar islands were close to center stage because they were so great for trade.
Is this second sentence entailed by the first?

Answer: it is not possible to tell

Sentence 1: But a board is nothing like Wall Street.

Sentence 2: Wall Street is just like a board.
Is this second sentence entailed by the first?

Answer: no

Sentence 1: Greuze pretended not to notice.

Sentence 2: Greuze acted as if he didn't notice.
Is this second sentence entailed by the first?

Answer:
yes