Premise:
"Even NASA's most enthusiastic supporters must admit that the early promise of this program has been unfulfilled."
Hypothesis: The early promise shown by the program hasn't been fulfilled.

yes

Premise:
"They've used the same pollster and seen the same Americans favor equal treatment of gays in the workplace but oppose gay marriage, probably because the latter involves sex."
Hypothesis: All Americans support gay marriage and have no problems with it.

no

Premise:
"On the island's west side, the Fontana Aretusa is a freshwater spring (just steps from the ocean) with black-and-white ducks swimming in its semi-circular papyrus pond."
Hypothesis: There are no freshwater springs located anywhere on the island.
no