Ineed .
(1) skyscrapers were made possible by two innovations in technology: structural steel (steel shaped for use in construction) and the elevator. (2) previously, buildings were supported by their walls. (3) large buildings had to be built with walls of heavy masonry (stonework or brickwork). (4) masonry walls made it difficult to put up structures higher than a hundred feet because the upper walls would weigh too much for the lower stories to bear. (5) steel changed all that completely. (6) the weight of the building could now be borne entirely by a light steel skeleton frame. (7) the outside walls, completely relieved from the duty of supporting weight, were now a mere “skin” and could be made of anything: tiles, metal panels, and glass. (8) and with the elevator, buildings could climb until they scraped the sky.
q. in sentence 6, the word borne means
a. held up.
b. replaced.
c. created.
d. increased.

[] Answer []

[] Explanation []

Sentence 6: "The weight of the building could now be borne entirely by a light steel skeleton frame."

Borne - Carried, held Up, Transported

The best definition of borne is option A, Held Up.

Option A tells us that the weight of the building could be held up entirely by just a light steel skeleton.

the present continuous is a verb tense which is mainly used to indicates that an action is in progress at the moment of speaking.  

it is formed using: person + verb to be (am/is/are) +verb + - ing form  

example: i am studying at this moment .

in addition, the present continuous is also used in order to express things that will or will not happen in the near future.

example: i am having dinner with some friends tonight.

the speaker sometimes   uses it   to express that an action is repeated and it causes irritation on the part of the speaker

example: my sister is constantly complaining about everything.