It refers to the era being described.
1 I could hardly believe it when the policeman told me what had happened.
2 It has been reported that a number of people in the area were affected.
3 It’s no use! I’ve looked everywhere for my wallet but I can’t find it anywhere.
4 We would appreciate it if you didn’t tell anyone about this.
5 It’s surprising how quickly I was able to master the skill.
6 It’s no wonder you couldn’t find your bag. You left it in the café.
A: ‘How much further is it?’
B: ‘It’s not far now.’
8 It’s a pity that you won’t be able to make it to the lunch.
9 It was a warm day for the time of year.
10 It appears that someone has made a mistake.
a) It was the best of times, It was the age of foolishness, etc, It was a warm day …, How much further is it?, It’s not far now
b) It’s no use …, It’s surprising …, It’s no wonder …, It’s a pity
c) It appears that someone …
d) It has been reported …
e) I could hardly believe it when …; I can’t find it anywhere; We would appreciate it if …; You left it in the café.
f ) you won’t be able to make it.
1 I can’t stand it when all it does is rain for days on end.
2 I’d appreciate it if you could give me a little more notice next time.
3 It’s no use just standing there. You’d better get on with it.
4 I find it hard to believe that the summer is here already.
5 It appears that the police have video footage of the incident.
6 It’s pointless arguing with her when she’s in that kind of state.
7 I’ll leave it to the others to decide what time we should meet.
8 I’ve always made it clear that my family has to take priority over my work.
1 It’s pointless crying about the situation now.
2 It’s essential to be trustworthy in this profession.
3 It seems (that) he has misplaced his keys.
4 We owe it to them to be hospitable as they were welcoming to us.
5 It’s no wonder she wasn’t very enthusiastic when she had heard the talk before.
6 I find it easy to keep abreast of the latest news online.
keep abreast of something: to make sure that you know all the most recent facts about a subject. E.g. It is almost impossible to keep abreast of all the latest developments in computing.
1 It’s difficult to believe he would have left all the money here.
2 It’s no wonder you were scared. That car nearly hit you.
3 It’s not my fault we didn’t finish on time. We started late.
4 I can’t help it if I keep making mistakes. Nobody’s perfect.
5 It’s important that we clear up any misunderstandings
6 It was a shame that we didn’t see the beginning.
7 It appears to have been a mistake.
8 It’s funny how things always turn out OK in the end.