The walls were substantial and did not fall.是什么意思？

The walls were substantial and did not fall.

墙很坚固, 没有倒塌。

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

walls

n. 墙( wall的名词复数 )，屏障，隔阂，壁垒；

例句
The walls were painted in muted tones to show the pictures to good advantage.
墙面被漆成了淡色调，以突出照片。

were

be的过去时复数和第二人称单数形式，有时代替 was,用于条件从句、动词 wish 之后等；

例句
Shops, houses, and vehicles were set ablaze.
店铺、房子和车辆全都陷于火海。

substantial

adj. 大量的，结实的，牢固的，重大的；

例句
Workers in big firms receive a substantial part of their pay in the form of bonuses and overtime.
大公司的员工有相当一部分薪酬来自奖金和加班费。

and

conj. 和，与，而且，于是，然后，因此；

例句
I spend a lot on expensive jewelry and clothing...
我花很多钱购买昂贵的首饰和衣服。

did

v. 做( do的过去式)，干，学习，研究；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

not

adv. 不，[用以表示否定、否认、拒绝、禁止等]不是，几乎不，未必，没有[用于否定后面的词或短语]；

例句
It became very clear that the incident was not just an aberration, it was not just a single incident.
事实已经很清楚，这件事不是偶发的，它并不是一起孤立的事件。

fall

v. 落下，跌倒，减少，沦陷；n. 落下，瀑布，秋天，减少；

例句
Whenever I get into a relationship, I always fall madly in love...
我每次谈恋爱都深陷其中，无法自拔。