8. Add conditional clauses as shown in brackets below to form mixed conditional sentences:
a)We wouldn't know as much about the universe as we do now if... (3rd conditional) b)If email hadn't been invented... (2nd conditional)
c)If we haven't discovered intelligent life on other planets by now... (1" conditional)
d)I'd be a lot better off today if... (3d conditional)
e)Venice wouldn't have become such a popular tourist destination if..........(2nd condition) ​