Premise:
"Impossible of course! "
Hypothesis: It is totally possible.

no

Premise:
"A few of these grand 19th- and 20th-century residences survive tucked away among the skyscrapers, the jungle often invading the gardens."
Hypothesis: A few of these residences still survive away from the skyscrapers.

yes

Premise:
"As in Hirosema, one of the most moving monuments is a single piece of masonry left standing."
Hypothesis: Hirosema only has a single piece of old masonry left.
yes