Hopefully in 2025 we will no longer be e﹣mailing each other, for we _______ more convenient electronic
communication tools by then.( )
have developed
had developed
will have developed
developed
Had the government limited the sales of cars much earlier, traffic jam and pollution _______so serious now.
____today, he would get there by Friday.
Had they known what was coming next, they _________second thoughts.
Had you taken it more seriously, you ________ such a silly mistake.
_________, the world would be more harmonious.