UnScramble this Word: i n n s e g c t?

Questions

It is said that caffeine is a proof positive remedy for waking up in the morning, however, there is something else that is more efficient? What is it?

The Volkswagen was originally called?

Which year did Niagara Falls freeze?

Name the two species that cannot walk backwards?

Where does the kangaroo’s tail have to be situated in order for it to jump?