Sentence 1: yeah yeah yeah i imaging he could play just about any position on the team except maybe a defensive lineman but he's a very excellent athlete

Sentence 2: I don't think he could be a defensive lineman because he is not big enough.
Is this second sentence entailed by the first?

Answer: it is not possible to tell

Sentence 1: That's the last bad stretch; now it'll be downhill an' green fields all th' way. Nye nodded at the narrow opening between two hills lying ahead.

Sentence 2: There's nothing but bad stretches left for us to go through.
Is this second sentence entailed by the first?

Answer: no

Sentence 1: In the opinion of many, Cuba is an isolated socialist dinosaur.

Sentence 2: Cuba is thought to be an isolated socialist dinosaur by many.
Is this second sentence entailed by the first?

Answer:
yes