Explanation:
The political scene has changed to a considerable amount over the most recent few decades. The web has played a vital role in this change. Social sites, specifically, are presently a genuine factor in political crusades and in the manner individuals consider issues.
Answer:
This is what the natural environment looks like for most people
Explanation:
The “urban ecosystem” serves as a research lab for scientist Gregory Glass, who studies the lives of the Charm City’s rats
Answer:
If everyone died, no one survived...
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!