THe second sentence is using present participle because you said " I promise" not "promised". Saying promise is when you are saying it at the time and saying promised means you've already said it. Like with how you said "kissed" instead of "kiss" in the first sentence.
Explanation:
<h2>jdjbdbdbxbdhdhddhjejejs
bye</h2>
1d) was designed (long time ago so past tense)
2d) Has been repaired (It is still going on the present, this year)
3c) Had discovered (He discovered America long time ago)
4a) To have worked (worked long ago when he was young)
Hope it helps!
