It can, as in ‘That’s life’, but in this sentence we need an equivalent to the third person singular.
“Life in the 21st century is easier than life (it) was in the past.”
Life in the 21st Century is easy. In the past, life (it) was harder."
They aren’t the same structure. ‘That’ is not followed by a verb in any of them.
You need a 1st/2nd/3rd person pronoun before the verb ‘used to be’ here. There is no subject pronoun for the verb otherwise.
You have to make a distinction between a comparison of actions (states) and a comparison of nouns. Look at this:
He will get much better exam results than his brother got. Here the comparison is between two ‘actions’ (will get and got) The two subjects - ‘he’ and ‘his brother’ both are followed by a verb.
In this sentence the comparison is between nouns:
He got a better result than that of his brother. In this sentence we are looking at the result of one brother in comparison with that of the other. Instead of repeating the noun ‘result’ we use the demonstrative pronoun ‘that’ and not a personal pronoun because there is no verb (action) involved.
No, you can’t. “Used to” (‘used’ here is a lexical verb) is quite different from “be used to” (‘used’ here is an adjective), both in structure and in meaning. More details on the difference can be found at bbc.co.uk/worldservice/learn … tv93.shtml
So what’s the comparison in the original sentence:
comparison between nouns or actions?
you and Beeesneees think “it” is right just because there is verb (action) involved and if there is no verb involed we should choose “that” . I wonder why can’t “that” be followed with verb in the sentence?
Life in the 21st century is easier than that in the past.
Life in the 21st century is easier than it was in the past.
His exam result is better than that of his brother.
Are those sentences OK?